A channel determination apparatus and method for a broadcast receiver are provided. The method includes estimating, when the broadcast receiver operates in a sleep state over a preset time period, inter-modulation distortion interference of a plurality of channels by scanning the channels, and receiving, when the sleep state is transitioned to an active state, broadcast data on a channel having the least inter-modulation distortion interference. Accordingly, the inter-modulation distortion interference of individual channels is taken into account to select an optimum channel, thereby resulting in improvement of channel determination accuracy.