CAT Balik Pulau (CT3) is a free bus service in Balik Pulau, Penang. It serves as a feeder bus route for the Balik Pulau neighbourhood. The route starts and ends at the Balik Pulau Bus Terminal, which serves as an interchange with bus 401, 401E, 403, 404 and 501. It goes as far as Politeknik Balik Pulau before making a U-turn back. The return journey covers different stretches of Jalan Pondok Upeh and Jalan Balik Pulau, but passes through Lintang Pondok Upeh twice.