Kavastu is a village in Luunja Parish, Tartu County, on the left bank of Emajõgi.
The only operating cable ferry in Estonia crosses the river at Kavastu. At Kavastu, there is a mediumwave transmitter with 2 249 metres tall guyed masts, actually used for broadcasting a religious program on 1035 kHz with 125 kW.
Historically, the village is named as Alevi and Uue-Kastre.