GZ may stand for:

• Gaza Strip: FIPS PUB 10-4 territory code
• DIN 19303 Code for Gestrichener Zellstoffkarton (German), a grade of paperboard also known as SBB, made from 'pigment coated', 'bleached virgin chemical pulp'
• Godzone - a phrase that has been used for more than 120 years by New Zealanders to describe their homeland.
• Ground Zero, in military parlance
• Guangzhou
• Guizhou, China
• Air Rarotonga IATA airline designator
• Righting torque, righting arm or GZ acting to restore a tilting ship to the vertical — see metacentric height 
• A leetspeak word meaning "congratulations" (from leetspeak "gratz")

Gzip is any of several software applications used for file compression and decompression. The term usually refers to the GNU Project's implementation, "gzip" standing for GNU zip. It is based on the DEFLATE algorithm, which is a combination of Lempel-Ziv (LZ77) and Huffman coding. The program was created by Jean-Loup Gailly and Mark Adler as a free software replacement for the compress program used in early Unix systems, and intended for use by the Project. Version 0.1 was first publicly released on October 30, 1992, and version 1.0 followed in February 1993.