Eight ships of the Royal Navy have been named HMS Ajax after the Greek hero Ajax:
- was a 74-gun third-rate ship of the line launched in 1767 and sold in 1785.
- was a 74-gun third rate launched in 1798. She fought at the Battle of Trafalgar in 1805 and was burned by accident in 1807.
- was a 74-gun third rate launched in 1809. She was converted to screw propulsion in 1846 and broken up in 1864.
- HMS Ajax was a 78-gun third rate launched in 1835 as . She was renamed HMS Ajax in 1867 and was broken up in 1875.
- was an battleship launched in 1880 and sold in 1904.
- was a battleship launched in 1912 and broken up in 1926.
- was a light cruiser launched in 1934. She took part in the Battle of the River Plate and was broken up in 1949.
- was a launched in 1962 and broken up in 1988.
- was an Admiralty barge built in 1956. She was moored at Jupiter Point on the Lynher River, Plymouth for seamanship training by from 1987 to 2008.
Battle Honours
- St. Vincent 1780
- St Kitts 1782
- The Saints 1782
- Egypt 1801
- Trafalgar 1805
- San Sebastian 1813
- Baltic 1854–55
- Jutland 1916
- River Plate 1939
- Mediterranean 1940–41
- Matapan 1941
- Greece 1941
- Crete 1941
- Malta Convoys 1941
- Aegean 1944
- Normandy 1944
- South France 1944
