Hoidas Lake is a small, remote northern lake in the Canadian province of Saskatchewan. It is about 7 kilometres (4.3 mi) south of the Saskatchewan–Northwest Territories border and 50 kilometres (31 mi) north of Uranium City in the Tazin River watershed. Named in honour of Irvin Frank Hoidas, a Royal Canadian Air Force pilot officer killed in action during the Second World War when his Stirling W-7520 crashed near the Belgian town of Sint-Truiden, it is the site of Canada's most advanced rare-earth element (REE) mining project.