Named in honor of Leo J. Scanlon (b. 1903), prominent amateur whose interest in astronomy was sparked by seeing comet 1P/Halley in 1910. A plumber by profession, he built his own astronomical equipment and instructed others in telescope making. With Chester B. Rowe he co-founded the Amateur Astronomers Association of Pittsburgh on 1929. The following year he built the first aluminum observatory dome. He observed variable stars, and he helped organize the Moonwatch team at the Allegheny Observatory in 1957. In 1985 he was happy to be able to observe comet 1P/Halley again. Name proposed by the discoverer, following a suggestion by T. P. Kohman, who prepared the citation.