Grøtsundet is a strait in the municipality of Tromsø in Troms, Norway. It separates the islands of Reinøya and Ringvassøya from the mainland. The strait has a width of 4–5 kilometres (2.5–3.1 mi).
Coordinates: 69°48′N 19°23′E / 69.80°N 19.39°E / 69.80; 19.39