William "Bill" Benjamin Lava (March 18, 1911 – February 20, 1971) was a composer and arranger who composed and conducted music for feature films as well as that for the Warner Bros.' Looney Tunes and Merrie Melodies animated cartoons from 1962 to 1969, replacing the deceased Milt Franklyn, making him the last composer and arranger in the classic era of Warner Bros. Cartoons.

Lava's music was markedly different from that of Franklyn and previous composer Carl Stalling, with a tendency towards atonality. A sense of tension is often created in Lava's scores using sequences based on the notes of the diminished seventh chord.

Lava also composed and sang the theme to the TV western series Cheyenne and composed the original theme from Gunsmoke.