Beauharnois is a city located in the Beauharnois-Salaberry Regional County Municipality of southwestern Quebec, Canada, and is part of Greater Montreal Area. The city's population as of the Canada 2011 Census was 12,011. It is home to the Beauharnois Hydroelectric Power Station, one of the largest hydroelectric generating stations in the world, as well as the Beauharnois Lock of the Saint Lawrence Seaway. In 2012, OVH started construction of its first Canadian data centre in Beauharnois, one of the largest in the world.