Helmdon is a village and civil parish about north of Brackley in West Northamptonshire, England.
The village is on the River Tove, which is flanked by meadows that separate the village into two. The parish includes the hamlets of Astwell and Falcutt and covers more than . The 2011 Census recorded a parish population of 899.
Manor
Helmdon's toponym is probably derived from Old English Helman denu "Helma's valley"; Helma is an unrecorded Old English masculine name. In the reign of Edward the Confessor two Saxons, Alwin and Godwin, held the manor "freely", i.e. without a feudal overlord. They were dispossessed after the Norman Conquest of England and the Domesday Book of 1086 records that Robert, Count of Mortain held a manor at "Elmedene". In 1562 George Lovett sold Helmdon to Lancelot Wilton of Brackley, who 16 months later sold it on to Magdalen College, Oxford. English Heritage dates the earliest building work to the 14th century It is a Grade II* listed building. south aisle, which may be early 13th-century. which in turn is part of the Benefice of the Astwell Group of Parishes.
The tower has a ring of six bells. Henry II Bagley of Chacombe cast the fourth, fifth and tenor bells in 1679. John Briant of Hertford In 1953 a schoolroom was added. and takes its name from the Cross family that ran it from then until late in the 18th century. Early in the 19th century Hopcroft and Norris's brewery in Brackley acquired it as a tied house. In 1872 it was taken over by Hopcroft and Norris, which in 1945 merged with the Chesham Brewery to form the Chesham and Brackley Brewery. just four years after the death of its namesake. In about 1884 it became a tied house of the Leamington Brewery Company and its name was changed to The Bell.
The Cock and Magpie in Wappenham Road opposite the Baptist chapel was trading by 1861. Its name was later shortened to the Magpie. Newspapers and magazines were donated and until 1930 a small annual subscription was charged. The original building included a house for the schoolmaster, which was sold as a private house in 1970.
Railways
thumb|Bridge carrying Station Road over the dismantled [[Stratford-upon-Avon and Midland Junction Railway next to the site of the former SMJR station]]
thumb|Helmdon Viaduct, part of the dismantled [[Great Central Main Line]]
In 1872 the Northampton and Banbury Junction Railway (from 1910 part of the Stratford-upon-Avon and Midland Junction Railway (SMJR)) was opened between and . It passed roughly east–west along the Tove Valley through the middle of the village, where its Helmdon station was opened.
In the 1890s a civil engineering contractor, Walter Scott and Company of Newcastle upon Tyne, built the section of the Great Central Main Line (GCML) between and . From 1894 to 1898 Scott had a construction yard in the Tove Valley at Helmdon with a network of sidings connected to the SMJR. It was next to where the company built Helmdon Viaduct, a nine-arch structure of Staffordshire blue brick that carried the GCML main line across the valley. In response the London and North Eastern Railway, which had succeeded the GCR in 1923, renamed its main line station "Helmdon for Sulgrave" from 1928.
British Railways closed the SMJR station and line in 1951, the GCML main line station in 1963 and the main line in 1966. Helmdon Viaduct survives.
Shops
In the late 19th and early 20th centuries Helmdon a dozen or more shops. By the 1930s they included a post office, three grocers, a butcher, an egg-dealer, a fruiterer, a baker, a newsagent, a tailor and a shoe repairer. as well as the primary school for children aged 4–11 years. The village has two ponds, and a public park with play equipment and benches. Helmdon won the Northamptonshire Village of the Year competition in 1969, 1996, 1999, 2002 and 2011.
thumb|[[Pillar box and community noticeboard in the part of the village north of the River Tove]]