Its civil parish council is, unusually in this district, shared with another village and is called Tidmarsh with Sulham.

The Pang flows north through the village and then through the Moor Copse Nature Reserve on its way to join the River Thames at Pangbourne.

[2] The Tidmarsh and Sulham circular walk, about 4.0 km (2.5 miles) long, passes through the reserve and both villages.

[4] There are multiple World War II pillboxes surrounding Tidmarsh, which made up part of the GHQ Line.

[10][11] Notable residents include author Lytton Strachey (1880–1932) and painter Dora Carrington (1893–1932), who lived in the Mill House between 1917 and 1924,[12] and mathematician John Pollard (born 1941).

[citation needed] Rex Partridge, renamed Ralph by the Bloomsbury set,[14] also settled at Tidmarsh and formed a very 'Bloomsbury' trio with Lytton and Dora.