Zack or Zach may refer to:
Zack is a 1920 play by British playwright Harold Brighouse.
It was one of several of Brighouse's plays performed by the Manchester's Gaiety Theatre.
Zack, Zac, or Zak is the name of a character in the original and new continuities of Battlestar Galactica.
Zac is the youngest child, son, of Adama and Ila. He was played by actor Rick Springfield.
Zak is the youngest child, son of William Adama and Caroline.