Actor. Born Larbert (Falkirk), the son of an iron founder, Finlayson was educated at George Watson's College in Edinburgh. He went on to study engineering at the University of Edinburgh with the intention of working with his father, but instead was drawn to the stage. He travelled to US with a group of touring players and began a career in films. Remembered for his obvious squint and handle-bar moustache, he appeared in a host of silent comedies through the 1920s, including several directed by Hal Roach. He is perhaps best remembered as the catalyst of chaos in a series of Laurel and Hardy films, including Flying Elephants (1927), Call of the Cuckoo (1927), Our Wife (1931), Pardon Us (1931), One Good Turn (1931), Pack Up Your Troubles (1932) and Block-Heads (1938). He continued appearing in films until 1951, including New Wine (1941) and Grand Canyon Trail (1948). He has been attributed as the source for the expression "D'oh" as used by Homer Simpson in the US cartoon The Simpsons.
He died in Los Angeles, California.