It is the fourth consecutive 500m gold for Nesbitt, of London, Ont. The 27-year-old skated to a cumulative time of 76.34 seconds in her two races and placed first twice, clocking in at 38.23 and 38.11 seconds, respectively.
Nesbitt said she knew where to pick up her game in order to pull away with the victory.
"The first race today was pretty good, but I knew I was missing something," Nesbitt said. "I was really happy that I was able to improve within one hour, skate a faster time and feel more powerful in the second race."
Winnipeg's Shannon Rempel picked up silver with a 77.27 total, and Danielle Wotherspoon, of Red Deer, Alta., took bronze with a cumulative time of 77.41. Wotherspoon was also last year's bronze medallist.
Jamie Gregg of Edmonton also defended his 500m title in the men's race. The three-time champion in the discipline skated to a personal-best time of 34.75 in the first race and placed first. He then came in at 34.60 in the second race to win with a total of 69.35.
"I'm definitely pleased with my time," Gregg said. "It's getting faster. I was having trouble at the start of the year finding my rhythm. In my last race I had a really good opener, it's a PB opener. Gilmore [Junio] was chasing me last year, and this year now I'm chasing him. We work well together as teammates."
Calgary's Junio was only 0.21 behind Gregg's total for the silver medal, posting in a total time of 69.56. Laurent Dubreuil, of Lévis, Que., claimed the bronze medal in a cumulative time of 69.66.
The Canadian championships will assist in selecting the teams for the Essent ISU sprint World Cup in Calgary starting on Jan. 19, the world sprint championships held on Jan. 26, and the three winter World Cups and final.