Balgö is an island and a nature reserve in Kattegat, off Tångaberg in Varberg Municipality, Sweden.

Balgö is the largest island in Halland.

Some smaller islands around Balgö are also included in the nature reserve.

Balgö is an important breeding and resting place for different birds, for example little tern, pied avocet and common eider.

Balgö has the largest population of natterjack toads in Halland.