William E. "Billy" May (November 10, 1916 – January 22, 2004) was an American composer, arranger and trumpeter. He composed film and television music for The Green Hornet (1966), Batman (with Batgirl theme, 1967), and Naked City (1960). He collaborated on films such as Pennies from Heaven (1981), and orchestrated Cocoon, and Cocoon: The Return, among others.

May also wrote arrangements for many top singers, including Frank Sinatra, Nat "King" Cole, Anita O'Day, Peggy Lee, Vic Damone, Bobby Darin, Johnny Mercer, Ella Fitzgerald, Jack Jones, Bing Crosby, Sandler and Young, Nancy Wilson, Rosemary Clooney, The Andrews Sisters and Ella Mae Morse. He also collaborated with satirist Stan Freberg on several classic 1950s and 1960s satirical music albums.