Louis Clark (born 27 February 1947, Kempson, Bedford, Bedfordshire, England) is a British musical arranger and keyboard player.

He trained at Leeds College of Music. He was the conductor of the orchestra and choir hired to back Electric Light Orchestra's sound, introduced on their album Eldorado in 1974. He assisted Jeff Lynne and Richard Tandy in writing string arrangements as well. He later played synthesizers for the band during their Time tour. In 1983 he returned to conduct the strings on the Secret Messages album. In 1986 he played Keyboards with ELO on their small number of live dates. Later he also joined the tour for ELO Part II in celebration of the band's 25th Anniversary.

In the early eighties he conducted the Royal Philharmonic Orchestra on a series of records under the title Hooked on Classics.