Louis R. Loeffler (February 24, 1897 – April 22, 1972) was an American film editor. Through his five-decade career, he worked on over one hundred films, including In Old Arizona (1928), In the Meantime, Darling (1944), Laura (1944), The Iron Curtain (1948), How to Marry a Millionaire (1953), River of No Return (1954), and Anatomy of a Murder (1959). He was nominated for two Academy Awards for film editing in 1960 and 1963 for the films Anatomy of a Murder and The Cardinal respectively.