Arthur Strettell Comyns Carr (19 September 1882 – 20 April 1965) was a British Liberal politician and lawyer.
Comyns Carr was the son of J. Comyns Carr, a dramatist and art critic. His mother, Alice Comyns Carr (1850–1927) was a costume designer for the theater. He was born in Marylebone and educated at Winchester College and Trinity College, Oxford. In 1907 he married Cicely Raikes Bromage, the daughter of a clergyman. They had three sons including Richard Strettell Comyns Carr who was the second husband of the avant garde English novelist Barbara Comyns Carr.
In 1908, Comyns Carr was called to the Bar at Grays Inn. He became a King’s Counsel in 1924, a Bencher of the Inn in 1938 and eventually Treasurer in 1951. Comyns Carr’s reputation as a barrister was confirmed in a libel action brought by Horatio Bottomley against an associate named Reuben Bigland. Carr’s cross-examination of Bottomley and another key witness destroyed his case and was instrumental in Bottomley’s eventual imprisonment on charges of fraud and his expulsion from the House of Commons. Comyns Carr later began to specialize in the law relating to local taxation and as a result of appearing in landmark rating appeals he was engaged as counsel to government departments. He also became an expert in the subject of national insurance. Much later Comyns Carr was a prosecutor in trials of German and Japanese war criminals, and he was knighted for this work in 1949.
At the outbreak of the First World War Comyns Carr he joined the Royal Naval Volunteer Reserve and later served on the staff at the Ministry of Munitions. He also acted as an adviser to the Ministry of Reconstruction. In the last months of the war he joined the army as a private soldier but did not serve overseas.