The 21-year-old won bronze in the final event of the Grand Prix season on the strength of a pair of 93.0-metre jumps for a total score of 216.4. Fellow Canadian Taylor Henrich also had a strong day, with a personal best seventh-place finish.
Japan's Sara Takanashi won the event with 224.7 points, and Slovenia's Katja Pozun won silver (222.0).
"My jumps today felt a lot better than yesterday," Tanaka said in a statement. "I jumped pretty well during the whole summer. This podium result is a huge boost for my self-confidence. I hope that the preparation for the winter and the Olympics go as well as the summer. My goal this summer and leading into the winter is consistency and I did that today."
Tanaka finished fourth overall in the Grand Prix standings.
"Atsuko’s podium this weekend is a huge result and demonstrates the depth of our team leading into this Olympic season," said Ski Jumping Canada High Performance Director Curtis Lyon. "...Currently we are not a targeted sport and thus receive no funding from Own the Podium; hopefully the results this summer will serve notice of our potential."