Walter Anthony Murphy, Jr. (born December 19, 1952) is an American composer, arranger, pianist, musician, and songwriter. He rose to fame with the hit instrumental "A Fifth of Beethoven", a disco adaptation of passages from the first movement of Ludwig van Beethoven's Fifth Symphony, in 1976, when disco was rising in popularity.

In a career spanning nearly four decades, Murphy has written music for numerous films and TV shows, including Stingray, Wiseguy, Hunter, The Commish, Profit, Buffy the Vampire Slayer, Channel Umptee-3, Changing Hearts, Looney Tunes, and Foodfight!. He has had a long association with Seth MacFarlane, composing the music for his films and TV shows such as Family Guy, The Cleveland Show, American Dad!, and Ted.