"Swearin' to God" is a song written by Bob Crewe and Denny Randell.

It was recorded by Frankie Valli and released in May 1975 as a single from his album Closeup.

[3][4][5][6] It is a love song whose lyrical hook is a more literal use of the expression "I swear to God" (i.e., "I mean this sincerely"): The first Valli song to incorporate the disco style (it runs four minutes as a single but just over ten minutes on the album),[5] "Swearin' to God" features Patti Austin singing a response to Valli's praise in the bridge.

[3][6] "Swearin' to God" hit number 6 on the U.S.

[7] Cash Box said of the edited single version that "Frankie's distinct vocal delivery meets a big, brassy arrangement and the result is a song that will surely skyrocket to the top.