ZG, Zg, or zg may refer to:
- Canton of Zug, one of the 26 cantons of Switzerland
- Viva Macau IATA code
- Zigong City name, in Sichuan province of China
- zettagram (written Zg, with capital "Z"), an SI unit of mass (equal to 10 g)
- zeptogram (written zg, with lower case "z"), an SI unit of mass (equal to 10 g) 1
- Z-G, a collectible action figure game
- Zagreb, the capital and the largest city of Croatia
- ZOEgirl, a pop rock band
- Zerstörergeschwader, a type of unit usually equipped with twin-engined fighters such as the Bf 110 or Me 410
- ZG, a Christian hip hop artist.
- ZG, "Zero Growth"
- ZG, The original license plate prefix designation for Aspen / Pitkin County, Colorado. Currently, the prefix "ZG" on license plates is rare and sought after as an iconic item in Aspen, Pitkin County and even throughout Colorado. The license plate designation "ZG" has so often been associated with Aspen that the letters "ZG" on stickers, tee shirts and the like are seen as synonymous with Aspen itself.