Jack Norworth (5 January, 1879 - 1 September, 1959) was a U.S. songwriter, singer, and vaudeville performer.

Norworth was born in Philadelphia, Pennsylvania.

He is credited as co-writer of a number of Tin Pan Alley hits. He wrote the lyrics of the song "Take Me Out to the Ball Game" in 1908, his most long lasting hit. His "Shine On, Harvest Moon" was an even bigger hit at the time; both had music by Albert Von Tilzer.

Other popular songs credited to Norworth include "Back To My Old Home Town"; "Come Along, My Mandy"; "Dear Dolly"; "Good Evening, Caroline"; "Holding Hands"; "Honey Boy"; "I'm Glad I'm A Boy/I'm Glad I'm A Girl"; "I'm Glad I'm Married"; "Kitty"; "Meet Me In Apple Blossom Time"; "Over on the Jersey Side"; "Since My Mother Was a Girl"; "Sing an Irish Song"; "Smarty"; and a sequel to "Shine On Harvest Moon" called "Turn Out Your Light, Mr. Moon Man".

He performed in the 1909 Ziegfeld Follies.

Norworth appeared in a number of Broadway theater productions, and later in movies.

In 1908 he married singer Nora Bayes, with who he performed on Vaudeville. Later he was married to actresses Louise Dresser, then to Dorothy Adelphi , who he appeared in early sound films with.

He died of a heart attack in Laguna Beach, California.

Norworth is an inductee in the Songwriters Hall of Fame.