The 25-year-old Montrealer hoisted a Games-record combined total of 250 kilograms — 110 in the snatch and another 140 in the clean and jerk.
Beauchemin-Nadeau was the silver medallist at the 2010 Commonwealth Games.
Mary Opeloge of Samoa was second Tuesday with a 243-kg total.
She was hoping to beat Beauchemin-Nadeau's 140 with her final lift in the clean and jerk but walked away from the 141-kilogram bar without making an attempt.
Apolonia Vaivai of Fiji took the bronze with 209 kilograms.
Beauchemin-Nadeau's gold was the second of the day for Canada in Glasgow. Catharine Pendrel won the women's mountain bike event, with teammate Emily Batty taking the silver.
Another silver went to shooter Jim Paton, who finished second in the Queen's Prize individual men's competition.
Wrestler Jasmine Mian added a bronze in the women's 48-kilogram class.