Walter Anthony Murphy Jr. (born December 19, 1952) is an American composer, keyboardist, songwriter, and record producer. He is best known for the instrumental "A Fifth of Beethoven", a disco adaptation of Beethoven's Fifth Symphony which topped the charts in 1976 and was featured on the Saturday Night Fever soundtrack in 1977. Further classical-disco fusions followed, such as "Flight '76", "Toccata and Funk in 'D' Minor" "Bolero", and "Mostly Mozart", but were not as successful.

In a career spanning over five decades, Murphy has written music for numerous films and TV shows, including The Tonight Show Starring Johnny Carson, The Savage Bees, Stingray, Wiseguy, The Commish, Profit, Buffy the Vampire Slayer, Looney Tunes, and How Murray Saved Christmas. He has had a long-running partnership with Seth MacFarlane, composing music for his films and TV shows such as Family Guy, American Dad, The Cleveland Show, Ted, Ted 2 and the Ted television series.