Cook Bay is the name of three bays:

• Cook Bay (South Georgia), in the subantarctic island of South Georgia
• Cook Bay (Antarctica), on the George V Coast
• Cook Bay (Tierra del Fuego) south of Tierra del Fuego

Cook's Bay is the southernmost bay of Lake Simcoe in Ontario, Canada. It is about 60 kilometres north of Toronto. The bay has some of the best fishing areas in North America, especially for yellow perch. The town of Keswick is the largest area that the bay has access to. Many marinas and motel accommodations are available. Many cottages are also present on the shores of the Northern half of the bay on both sides.