"Saturday Night (Is the Loneliest Night of the Week)" is a popular song.
The music was written by Jule Styne with lyrics by Sammy Cahn. The song was published in 1944.
The song is best known in a version by Frank Sinatra (recorded November 14, 1944, released by Columbia Records as catalog number 36762, with the flip side "I Dream of You (More than You Dream I Do)"), but has been recorded by a number of other artists, including Barry Manilow and Rosemary Clooney.
References
Saturday Night (Is the Loneliest Night of the Week) Wikipedia(Text) CC BY-SA