Mayme and her sister Janie work as salesgirls in Ginsberg's Department Store.  Mayme is in love with Bill, a clerk, but Janie tries to steal him away.

As treasurer of the Employees' Welfare Club pageant, Janie gets into trouble because she uses the club money to make a bet on the horse races.  She tells her sister about her predicament, and Mayme goes to Janie's bookie and wins the money back in a dice game.  However, Janie has been asked for the club money and she falsely accuses Mayme of taking it.  Mayme returns with the money and learns that Bill has sold his radio to help pay back the loss.  She tells off her ungrateful sister.  Hearing the truth, Bill rejects Janie and plans marriage with Mayme.

What was said about The Saturday Night Kid:

New York Herald Tribune (Richard Watts, Jr.)
"Miss Clara Bow's newest vehicle is a screen adaptation of that amusing play of several seasons ago, Love 'Em and Leave 'Em.  It is, in the present version, considerably less than a masterpiece; yet, as a result of some amusing department store scenes and excellent performances by Miss Bow, Miss Jean Arthur and Miss Edna May Oliver, it becomes an unostentatious, but reasonably pleasant entertainment."

The Films of Jean Harlow
by Michael Conway and Mark Ricci
Bonanza Books, New York 1965