Zachary "Zach" Grossack (born 1997) is an American professional bridge player from Boston.

He is currently the youngest Grand Life Master in the American Contract Bridge League (ACBL).

Zach was on the cover of the ACBL Bulletin (monthly magazine) in October 2019 and February 2023.

He was the ACBL Player of the Year (winner of the most platinum Masterpoints in North American Bridge Championship) for 2022.

He has two brothers, Adam, who is also a Bridge player, and Sam.