This is a list of monitors of the Royal Navy of the United Kingdom.
Key
{| class="wikitable"
|-
| Main guns
| The number and type of the main battery guns
|-
| Displacement
| Ship displacement at standard combat load
|-
| Propulsion
| Number of shafts, type of propulsion system
|-
| Laid down
| The date the keel began to be assembled
|-
| Commissioned
| The date the ship was commissioned
|-
| Fate
| The fate of the ship
|}
Humber-class
thumb|left|alt=|HMS Humber
The Humber-class monitors were three river monitors under construction for the Brazilian Navy in Britain in 1913, all three were taken over by the Royal Navy shortly before the outbreak of the First World War and were commissioned as small monitors, seeing extensive service during the war.
{| class="wikitable" style="width:98%;"
|- valign="top"|- valign="top"
! style="width:15%; text-align:center;" rowspan="2"| Ship
! style="width:10%; text-align:center;" rowspan="2"| Main guns
! style="width:10%; text-align:center;" rowspan="2"| Displacement
! style="width:20%; text-align:center;" rowspan="2"| Propulsion
! style="width:40%; text-align:center;" colspan="3"| Service
|- valign="top"
! style="width:10%; text-align:center;"| Laid down
! style="width:10%; text-align:center;"|Acquired
! style="width:20%; text-align:center;"|Fate
|- valign="top"
| align= left | (ex-Javary)
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />triple expansion engines<br />2 × boilers
| style="text-align:center;"|24 Aug 1912
| style="text-align:center;"|8 Aug 1914
| align= left |Sold to F. Rijsdijk 17 Sep 1920 for use as a crane lighter
|- valign="top"
| align= left | (ex-Madeira)
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />triple expansion engines<br />2 × boilers
| style="text-align:center;"|24 Aug 1912
| style="text-align:center;"|3 Aug 1914
| align= left |Sold for scrap 1921
|- valign="top"
| align= left | (ex-Solimoes)
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />triple expansion engines<br />2 × boilers
| style="text-align:center;"|24 Aug 1912
| style="text-align:center;"|8 Aug 1914
| align= left |Sold for scrap 9 May 1921
|}
Abercrombie-class
thumb|alt=|HMS Havelock
The Abercrombie-class monitors came about when Bethlehem Steel in the United States, the contracted supplier of the main armament for the Greek battleship being built in Germany, instead offered to sell the four 14"/45 caliber gun twin gun turrets to the Royal Navy on 3 November 1914, the ships were laid down and launched within six months, seeing service throughout the war.
{| class="wikitable" style="width:98%;"
|- valign="top"|- valign="top"
! style="width:15%; text-align:center;" rowspan="2"| Ship
! style="width:10%; text-align:center;" rowspan="2"| Main guns
! style="width:10%; text-align:center;" rowspan="2"| Displacement
! style="width:20%; text-align:center;" rowspan="2"| Propulsion
! style="width:40%; text-align:center;" colspan="3"| Service
|- valign="top"
! style="width:10%; text-align:center;"| Laid down
! style="width:10%; text-align:center;"|Commissioned
! style="width:20%; text-align:center;"|Fate
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × vertical triple expansion reciprocating engines<br />2 × boilers
| style="text-align:center;"|12 Dec 1914
| style="text-align:center;"|1 May 1915
| align= left |Sold for scrap 25 Jun 1927
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × vertical triple expansion reciprocating engines<br />2 × boilers
| style="text-align:center;"|12 Dec 1914
| style="text-align:center;"|May 1915
| align= left |Sold for scrap 25 Jun 1921
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × vertical triple expansion reciprocating engines<br />2 × boilers
| style="text-align:center;"|1 Dec 1914
| style="text-align:center;"|May 1915
| align= left |Sunk 20 Jan 1918
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × vertical triple expansion reciprocating engines<br />2 × boilers
| style="text-align:center;"|17 Dec 1914
| style="text-align:center;"|21 May 1915
| align= left |Sold for scrap Sep 1936
|}
Lord Clive-class
thumb|alt=|HMS Earl of Peterborough
The Lord Clive-class monitors, sometimes referred to as the General Wolfe-class, were built to meet the need for more shore bombardment ships, using twin gun turrets taken from decommissioned Majestic-class pre-dreadnought battleships. Three of the ships, HMS General Wolfe, Lord Clive and Prince Eugene, were converted to take the BL 18 inch Mk I naval gun that had originally been allocated to .
{| class="wikitable" style="width:98%;"
|- valign="top"|- valign="top"
! style="width:15%; text-align:center;" rowspan="2"| Ship
! style="width:10%; text-align:center;" rowspan="2"| Main guns
! style="width:10%; text-align:center;" rowspan="2"| Displacement
! style="width:20%; text-align:center;" rowspan="2"| Propulsion
! style="width:40%; text-align:center;" colspan="3"| Service
|- valign="top"
! style="width:10%; text-align:center;"| Laid down
! style="width:10%; text-align:center;"|Acquired
! style="width:20%; text-align:center;"|Fate
|- valign="top"
| align= left |
| style="text-align:center;"| 2 × <br>later also <br>1 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />reciprocating steam engines<br />2 × boilers
| style="text-align:center;"|9 January 1915
| style="text-align:center;"|10 July 1915
| align= left |Sold for scrap 10 October 1927
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />reciprocating steam engines<br />2 × boilers
| style="text-align:center;"|9 January 1915
| style="text-align:center;"|26 August 1915
| align= left |Sold for scrap 1921
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />reciprocating steam engines<br />2 × boilers
| style="text-align:center;"|16 January 1915
| style="text-align:center;"|23 September 1915
| align= left |Sold for scrap 1921
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />reciprocating steam engines<br />2 × boilers
| style="text-align:center;"|16 January 1915
| style="text-align:center;"|30 September 1915
| align= left |Sold for scrap 1921
|- valign="top"
| align= left |
| style="text-align:center;"| 2 × <br>conversion to <br>1 × <br> incomplete at armistice
| style="text-align:center;"|
| align= left |2 × shafts<br />reciprocating steam engines<br />2 × boilers
| style="text-align:center;"|1 February 1915
| style="text-align:center;"|September 1915
| align= left |Sold for scrap 1921
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />reciprocating steam engines<br />2 × boilers
| style="text-align:center;"|12 January 1915
| style="text-align:center;"|May 1915
| align= left |Sold for scrap 1923
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />reciprocating steam engines<br />2 × boilers
| style="text-align:center;"|13 January 1915
| style="text-align:center;"|May 1915
| align= left |Sold for scrap 1921
|- valign="top"
| align= left |
| style="text-align:center;"| 2 × <br>later also <br>1 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />reciprocating steam engines<br />2 × boilers
| style="text-align:center;"|January 1915
| style="text-align:center;"|27 October 1915
| align= left |Sold for scrap 1923
|}
Marshal Ney-class
thumb|alt=|HMS Marshal Ney
The Marshal Ney-class monitors were built to use the two modern 15-inch turrets made available by the redesign of and as battlecruisers.
{| class="wikitable" style="width:98%;"
|- valign="top"|- valign="top"
! style="width:15%; text-align:center;" rowspan="2"| Ship
! style="width:10%; text-align:center;" rowspan="2"| Main guns
! style="width:10%; text-align:center;" rowspan="2"| Displacement
! style="width:20%; text-align:center;" rowspan="2"| Propulsion
! style="width:40%; text-align:center;" colspan="3"| Service
|- valign="top"
! style="width:10%; text-align:center;"| Laid down
! style="width:10%; text-align:center;"|Commissioned
! style="width:20%; text-align:center;"|Fate
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />Diesel engines
| style="text-align:center;"|
| style="text-align:center;"|August 1918
| align= left |Sold for scrap 10 July 1946
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />Diesel engines
| style="text-align:center;"|
| style="text-align:center;"|August 1915
| align= left |Sold for scrap 1957
|}
Gorgon-class
thumb|alt=|HMS Glatton
The Gorgon-class monitors were originally built as coastal defence ships for the Royal Norwegian Navy, but requisitioned for British use.
{| class="wikitable" style="width:98%;"
|- valign="top"|- valign="top"
! style="width:15%; text-align:center;" rowspan="2"| Ship
! style="width:10%; text-align:center;" rowspan="2"| Main guns
! style="width:10%; text-align:center;" rowspan="2"| Displacement
! style="width:20%; text-align:center;" rowspan="2"| Propulsion
! style="width:40%; text-align:center;" colspan="3"| Service
|- valign="top"
! style="width:10%; text-align:center;"| Laid down
! style="width:10%; text-align:center;"|Commissioned
! style="width:20%; text-align:center;"|Fate
|- valign="top"
| align= left | (ex-Nidaros)
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />Vertical triple-expansion steam engines<br />4 × boilers
| style="text-align:center;"|11 June 1913
| style="text-align:center;"|1 May 1918
| align= left |Sold for scrap 26 August 1928
|- valign="top"
| align= left | (ex-Bjørgvin)
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />Vertical triple-expansion steam engines<br />4 × boilers
| style="text-align:center;"|26 May 1913
| style="text-align:center;"|31 August 1918
| align= left |Wrecked by explosion 16 September 1918, 79 killed
|}
M15-class
thumb|alt=|HMS M15
The M15-class monitors were fourteen ships ordered in March 1915, as part of the War Emergency Programme of ship construction, mounting 9.2 inch Mk VI gun turrets removed from the and the Mk X turrets held in stock for the and s.
{| class="wikitable" style="width:98%;"
|- valign="top"|- valign="top"
! style="width:15%; text-align:center;" rowspan="2"| Ship
! style="width:10%; text-align:center;" rowspan="2"| Main guns
! style="width:10%; text-align:center;" rowspan="2"| Displacement
! style="width:20%; text-align:center;" rowspan="2"| Propulsion
! style="width:40%; text-align:center;" colspan="3"| Service
|- valign="top"
! style="width:10%; text-align:center;"| Laid down
! style="width:10%; text-align:center;"|Commissioned
! style="width:20%; text-align:center;"|Fate
|- valign="top"
| align= left |
| style="text-align:center;"| 1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />4-cylinder semi-diesel engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|June 1915
| align= left |Sunk by on 11 November 1917, 26 killed.
|- valign="top"
| align= left |
| style="text-align:center;"| 1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />4-cylinder semi-diesel engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|June 1915
| align= left |Sold 29 January 1920
|- valign="top"
| align= left |
| style="text-align:center;"| 1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />4-cylinder semi-diesel engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|June 1915
| align= left |Sold 12 May 1920
|- valign="top"
| align= left |
| style="text-align:center;"| 1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />4-cylinder semi-diesel engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|July 1915
| align= left |Sold 29 January 1920
|- valign="top"
| align= left |
| style="text-align:center;"| 1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />4-cylinder semi-diesel engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|June 1915
| align= left |Sold 12 May 1920
|- valign="top"
| align= left |
| style="text-align:center;"| 1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />4-cylinder semi-diesel engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|July 1915
| align= left |Sold 29 January 1920
|- valign="top"
| align= left |
| style="text-align:center;"| 1 × <br>later <br>1 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />Triple Expansion steam engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|July 1915
| align= left |Sunk 20 October 1918 off Dover
|- valign="top"
| align= left | (later HMS Medea)
| style="text-align:center;"| 1 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />Triple Expansion steam engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|August 1915
| align= left |Converted to a minelayer in 1920, renamed HMS Medea 1925, became a training ship 1937, sold 1938, wrecked 2 January 1939
|- valign="top"
| align= left | (later RNVR Claverhouse)
| style="text-align:center;"| 1 × <br>later <br>1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />4-cylinder semi-diesel engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|July 1915
| align= left |Became a Royal Naval Volunteer Reserve drillship, and was renamed Claverhouse in 1922, sold 1959
|- valign="top"
| align= left |
| style="text-align:center;"| 1 × <br>later <br>1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />Campbell 4-cylinder paraffin engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|August 1915
| align= left |Sold 29 January 1920 for conversion to a mercantile oil tanker, and renamed Satoe
|- valign="top"
| align= left |
| style="text-align:center;"| 1 × <br>later <br>1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />4-cylinder semi-diesel engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|September 1915
| align= left |Scuttled in the Dvina River 16 September 1919
|- valign="top"
| align= left |
| style="text-align:center;"| 1 × <br>later <br>1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />4-cylinder semi-diesel engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|October 1915
| align= left |Sold 29 January 1920
|- valign="top"
| align= left |
| style="text-align:center;"| 1 × <br>later <br>1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />4-cylinder semi-diesel engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|November 1915
| align= left |Scuttled in the Dvina River 16 September 1919
|- valign="top"
| align= left |
| style="text-align:center;"| 1 × <br>later <br>1 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />4-cylinder semi-diesel engines
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|August 1915
| align= left |Sunk during the Battle of Imbros on 20 January 1918, 11 killed
|}
M29-class
thumb|alt=|HMS M30
The M29-class monitors were five ships ordered in March 1915, as part of the War Emergency Programme of ship construction.
{| class="wikitable" style="width:98%;"
|- valign="top"|- valign="top"
! style="width:15%; text-align:center;" rowspan="2"| Ship
! style="width:10%; text-align:center;" rowspan="2"| Main guns
! style="width:10%; text-align:center;" rowspan="2"| Displacement
! style="width:20%; text-align:center;" rowspan="2"| Propulsion
! style="width:40%; text-align:center;" colspan="3"| Service
|- valign="top"
! style="width:10%; text-align:center;"| Laid down
! style="width:10%; text-align:center;"|Commissioned
! style="width:20%; text-align:center;"|Fate
|- valign="top"
| align= left | (later HMS Medusa, HMS Talbot & HMS Medway II)
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />Triple expansion engines. Oil fuel 45 tons boilers
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|June 1915
| align= left |Converted to minelayer and renames HMS Medusa in 1925, converted to a repair ship and became the depot ship and renames HMS Talbot in 1941, again renamed HMS Medway II in 1944, sold in December 1946 for breaking
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />Triple expansion engines. Oil fuel 45 tons boilers
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|July 1915
| align= left |Sunk by shore batteries at the Gulf of Smyrna 14 May 1916
|- valign="top"
| align= left | (later HMS Melpomene, then HMS Menelaus)
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />Triple expansion engines. Oil fuel 45 tons boilers
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|July 1915
| align= left |Converted to minelayer in 1923, renamed HMS Melpomene in 1925, converted to a torpedo training vessel in 1939, renamed HMS Menelaus in 1941, in 1944, sold in 1948 for breaking
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />Triple expansion engines. Oil fuel 45 tons boilers
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|June 1915
| align= left |Sold in January 1920 for use as an oil tanker, and named Ampat
|- valign="top"
| align= left | (later HMS Minerva and Hulk C23)
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |4 × shafts<br />Triple expansion engines. Oil fuel 45 tons boilers
| style="text-align:center;"|1 March 1915
| style="text-align:center;"|June 1915
| align= left |Converted to mine-laying training ship and was renamed HMS Minerva in 1925, later became a fuelling hulk and boom defence workshop, renamed Hulk C23, currently museum ship at Portsmouth
|}
Erebus-class
thumb|alt=|HMS Terror
The Erebus-class monitors were two ships mounting a single twin BL 15 inch Mk I naval gun turret. They saw active service in World War I off the Belgian coast, were placed in reserve between the wars then served in World War II, with Terror being lost in 1941 and Erebus surviving to be scrapped in 1946.
{| class="wikitable" style="width:98%;"
|- valign="top"|- valign="top"
! style="width:15%; text-align:center;" rowspan="2"| Ship
! style="width:10%; text-align:center;" rowspan="2"| Main guns
! style="width:10%; text-align:center;" rowspan="2"| Displacement
! style="width:20%; text-align:center;" rowspan="2"| Propulsion
! style="width:40%; text-align:center;" colspan="3"| Service
|- valign="top"
! style="width:10%; text-align:center;"| Laid down
! style="width:10%; text-align:center;"|Commissioned
! style="width:20%; text-align:center;"|Fate
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />4 x oil-fired boilers
| style="text-align:center;"|12 October 1915
| style="text-align:center;"|2 September 1916
| align= left |Scrapped July 1946
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />4 x oil-fired boilers
| style="text-align:center;"|26 October 1915
| style="text-align:center;"|6 August 1916
| align= left |Sunk 23 February 1941 off Derna, Libya
|}
Roberts-class
thumb|alt=|HMS Abercrombie
The Roberts-class monitors were two ships mounting a single twin BL 15 inch Mk I naval gun turret built during the Second World War, featuring shallow draught for operating inshore, broad beam to give stability and a high observation platform to observe fall of shot.
{| class="wikitable" style="width:98%;"
|- valign="top"|- valign="top"
! style="width:15%; text-align:center;" rowspan="2"| Ship
! style="width:10%; text-align:center;" rowspan="2"| Main guns
! style="width:10%; text-align:center;" rowspan="2"| Displacement
! style="width:20%; text-align:center;" rowspan="2"| Propulsion
! style="width:40%; text-align:center;" colspan="3"| Service
|- valign="top"
! style="width:10%; text-align:center;"| Laid down
! style="width:10%; text-align:center;"|Commissioned
! style="width:20%; text-align:center;"|Fate
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />2 × Parsons steam turbines<br />2 × boilers
| style="text-align:center;"|30 April 1940
| style="text-align:center;"|27 October 1941
| align= left |Sold for scrap June 1965
|- valign="top"
| align= left |
| style="text-align:center;"| 2 ×
| style="text-align:center;"|
| align= left |2 × shafts<br />2 × Parsons steam turbines<br />2 × boilers
| style="text-align:center;"|26 April 1941
| style="text-align:center;"|5 May 1943
| align= left |Scrapped 24 December 1954
|}
See also
- List of monitors of the United States Navy