The son of the Right Reverend Walter Ruthven Pym, Bishop of Bombay, Pym was educated at Bedford School and Magdalene College, Cambridge. He was elected as Member of Parliament (MP) for Monmouth in Wales at a by-election in 1939. He represented the constituency in the House of Commons until his death during the 1945 general election. Polling took place on 5 July 1945. Pym died 12 days later, but nine days before the declaration of the result. He was declared posthumously elected on 26 July 1945, provoking a by-election in his Monmouth constituency. That contest was won by Peter Thorneycroft.
Leslie Pym died on 17 July 1945, three days before his brother, Revd Canon Thomas Wentworth Pym, and, coincidentally, on the same day as Sir Edward Campbell, the member for Bromley, who was also posthumously elected.
- Craig, F. W. S. (1983) . British parliamentary election results 1918-1949 (3rd ed.). Chichester: Parliamentary Research Services. ISBN 0-900178-06-X.
- Leigh Rayment's Historical List of MPs
- Hansard 1803–2005: contributions in Parliament by Leslie Pym
|Parliament of the United Kingdom|
John Arthur Herbert
| Member of Parliament for Monmouth