“It’s a Sin to Tell a Lie” is a 1936 popular song written by Billy Mayhew,introduced early that year on records by many dance bands including Dick Robertson on the 78rpm record Champion 40106, and later popularized by Fats Waller on Victor 25342 and re-issued on Victor 20-1595. It was recorded in French by Cajun singer ClĂ©oma Breaux in 1936 or 1937 Four further recordings of the song were made in 1936, namely by Freddy Ellis and His Orchestra (April), Victor Young and His Orchestra (April), Elton Britt (September), Roy Smeck and His Serenaders and Vera Lynn.