Ross MacManus (20 October 1927 – 24 November 2011), born Ronald Patrick Ross McManus, was an English musician and trumpet player of Irish descent. He performed with Joe Loss and his orchestra. He was the father of Elvis Costello.
MacManus was born on Conway Street, Birkenhead, to Mabel and Pat McManus. He began singing at the age of nine as a chorister at St Thomas's Roman Catholic Church. He attended Saint Anselm's College. He later adapted his surname to MacManus.
Prior to joining Joe Loss, he had his own band, which sometimes played at the Mecca Locarno dance hall in Leeds. He later joined Joe Loss in March 1955. He wrote and sang "Patsy Girl", a 1964 single credited to Ross McManus and the Joe Loss Blue Beats. The song was featured on the "Fathers" episode of Bob Dylan's radio series, Theme Time Radio Hour, in 2006. In 1970 he recorded a version of The Beatles' song "The Long and Winding Road" under the pseudonym of Day Costello, which spent 17 weeks in the Australian charts, peaking at number 16.
MacManus was responsible for the music and vocals from the R. White's Lemonade television advertisement theme song, "Secret Lemonade Drinker", on which Costello plays the drums, and sang backing vocals.
In 1976, he wrote and sang a number of songs for the soundtrack to the British film Secrets of a Superstud.
He played the trumpet on two of Elvis Costello's albums: on Out of Our Idiot (1987) the song "A Town Called Big Nothing", credited to the MacManus Gang and originally recorded for the film Straight to Hell, and on Mighty Like a Rose (1991) the song "Invasion Hit Parade". His 1972 album of cover versions of Elvis Presley songs, Elvis Presley's Golden Hits Sung By Big Ross & The Memphis Sound, was reissued on CD in 2008 as Elvis' Dad Sings Elvis.