TAG Heuer S.A. (English pronunciation: /ˌtæɡ ˈhɔɪ.ər/ tag hoy-ər) is a Swiss manufacturing company that designs, manufactures and markets watches and fashion accessories as well as eyewear and mobile phones manufactured under license by other companies and carrying the Tag Heuer brand name.

TAG Heuer began as Uhrenmanufaktur Heuer AG, founded in 1860 by Edouard Heuer in St-Imier, Switzerland. In 1985 TAG Group purchased a majority stake in the company, forming TAG Heuer. In 1999 French luxury goods conglomerate LVMH bought nearly 100 percent of the Swiss company.

The name TAG Heuer combines the initials of "Techniques d'Avant Garde" and the founder's surname.