Lionel Leonard Cohen, Baron Cohen PC (1 March 1888 – 9 May 1973), was a British judge.
Invested to the Privy Council in 1946, Cohen was Lord Justice of Appeal from 1946 to 1951. On 12 November 1951, he was appointed Lord of Appeal in Ordinary and made additionally a life peer with the title Baron Cohen, of Walmer in the County of Kent. In 1960, he retired as Lord of Appeal.
Cohen chaired many Royal Commissions in the years following World War II, particularly the Report of the Committee on Company Law Amendment in 1945 and on compensation. From 1946 to 1956 he chaired the Royal Commission on Awards to Inventors, which acknowledged scientists who had made technological advances such as radar and the jet engine during the war. He also headed the Cohen Inquiry into the loss of de Havilland Comet airliners Yoke Peter and Yoke Yoke in 1954.
Cohen was married with two sons and one daughter.