Roes Welcome Sound is a long channel at the northwest end of Hudson Bay in Kivalliq Region, Nunavut, Canada between the mainland on the west and Southampton Island on the east. It opens south into Hudson Bay. Its north end joins Repulse Bay which is connected east through Frozen Strait to Foxe Basin, thereby making Southampton Island an island. Wager Bay is a western branch. It is situated 200 km (120 mi) north of Marble Island.