William Russell Watrous III (born June 8, 1939 in Middletown, Connecticut) is a jazz trombonist. He is perhaps best known by casual fans of jazz music for his rendition of Sammy Nestico's arrangement of the Johnny Mandel ballad "A Time for Love," which he recorded on a 1993 album of the same name. A self-described "bop-oriented" player, he is well known among fellow trombonists as a master technician and for his mellifluous sound.