Viiratsi (before 1920: Wieratz) is a small borough () in Viljandi Parish, Viljandi County, Estonia. As of the 2011 census, the settlement's population was 1,332.
The Commander-in-chief of the Estonian Army Johan Laidoner (1884âÂÂ1953) was born in Raja farmstead near Viiratsi, site now located in nearby Vardja village.