Alan David Walder (13 November 1928 – 26 October 1978) was a British Conservative Party politician.
Born in St Pancras, London, Walder was educated at Latymer School and Christ Church, Oxford. He was commissioned into the Royal Artillery in 1948. In 1953 he transferred to the 4th Hussars (Army Emergency Reserve) and was promoted lieutenant. He was promoted captain in 1956. He became a barrister, called to the bar by Inner Temple in 1956.
He unsuccessfully contested the Leicester South West constituency at the 1959 general election. He was elected Member of Parliament (MP) for High Peak at a 1961 by-election, but lost the seat at the 1966 general election, to Labour's Peter Jackson.
He was returned to the House of Commons at the 1970 general election as MP for Clitheroe, which he held until his death in Chelsea in 1978 at the age of 49. Walder was an assistant government whip from 1973 to 1974.
Walder's successor at the by-election after his death was David Waddington.
Walder was also a noted author and military historian. His works included humorous fiction relating primarily to his experiences in the army and politics, and comprised:
- Bags of Swank (1963)
- The Short List (1964)
- The House Party (1966)
- The Fair Ladies of Salamanca (1967)
- The Chanak Affair (1969)
- The Short Victorious War: Russo-Japanese Conflict 1904–5 (1973)
- Nelson (1978).
- Times Guide to the House of Commons October 1974
- Leigh Rayment's Historical List of MPs