Santo J. "Sonny" Russo (March 20, 1929 – February 23, 2013) was an American jazz trombonist.

Russo grew up in a musical family; both his father and grandfather were professional horn players. He first played piano and violin, and played with his father's group at age 15. He had a long list of associations with noted jazz musicians; he started out with Buddy Morrow in 1947, and then played with Lee Castle (1948), Sam Donahue (1949), Artie Shaw (1949–50), Art Mooney (1950), Tito Puente, Jerry Wald, Tommy Tucker, Buddy Rich, Ralph Flanagan (1951–52), the Sauter-Finegan Orchestra (1953–55), Neal Hefti (1954–55), Jimmy Dorsey and Tommy Dorsey (1955–56), and Maynard Ferguson (1956). Starting in the mid-1950s Russo found work in the bands of various Broadway shows. In the late 1950s and 1960s he worked with Louie Bellson (1957), Machito, Bobby Hackett, Benny Goodman, and Doc Severinsen (1967). From 1969 to 1972 he was a member of The Tonight Show orchestra, and he worked with Frank Sinatra from 1967 to 1988. He also played in Urbie Green's 21 Trombones in 1968 and in the World's Greatest Jazz Band in the 1970s. While touring with The World's Greatest Jazz Band Russo was invited to the White House to play for President and Mrs.Ford.

Russo also recorded extensively with singers; in addition to Sinatra, he played behind Jimmy Rushing, Tony Bennett, Lena Horne, Perry Como, Dinah Washington, Liza Minnelli, Elvis Presley, Paul Anka, Ray Charles, Steve Lawrence, and Eydie Gorme. Sonny also performs on the soundtracks to the films The Godfather, The Godfather II, Goodfellas, and Sophie's Choice. In 1971 during a performance on The Tonight Show Starring Johnny Carson with Louis Armstrong as one of the guests, Russo shared the stage with Louis in which he played the solo on the tune "Someday You'll Be Sorry". Russo was also a fixture in the recording studios for radio and television. Also, while Jerry Lewis was doing the Muscular Dystrophy Telethon in New York City, Russo was a regular in the Orchestra always in demand he later worked with Lewis while Lewis performed his one-man show in Upstate New York. While touring around the world with Frank Sinatra during their performance and filming of Concert of the Americas, Russo played the trombone solo on the tune "I've Got You Under My Skin and was announced by Sinatra during the performance. He has also done many Jazz gigs with the likes of Al Cohn, Zoot Simms, Mousey Alexander, and Milt Hinton.