Zack is the short form of Zachary, from the Hebrew Zekharyah, "the Lord remembers". In the 1980s and 1990s American parents began giving the nickname on its own, and the spelling with ck felt punchier than Zach. Zack entered the US top 1000 in 2002, peaked at number 889 in 2008 and has since slipped back; in 2025 it ranks 1435 for boys.