Gaiarine is a comune (municipality) in the province of Treviso, in the Italian region of Veneto, about 50 kilometres (31 mi) north of Venice and about 30 kilometres (19 mi) northeast of Treviso.

Gaiarine borders these municipalities: Brugnera, Codogné, Cordignano, Fontanelle, Godega di Sant'Urbano, Mansuè, Orsago, Portobuffolé, Sacile. Its hamlets are Francenigo, Albina, Campomolino and Calderano.