Frobisher Bay, inlet of the North Atlantic Ocean extending into southeastern Baffin Island, Nunavut territory, Canada. The bay is about 150 miles (240 km) long and 20–40 miles (32–64 km) wide and has a maximum depth of 400 feet (120 metres). It was discovered in 1576 by Sir Martin Frobisher, who believed it to be a strait. It was identified as a bay in 1860. The city of Iqaluit at the head of the bay is the capital of Nunavut territory and the headquarters of Baffin region.