Wolfgang Goffing, 44, was arrested after a woman reported him to a Canada Line attendant at around 9 a.m. PT Monday.
The woman told police she had boarded a crowded train heading northbound at the Yaletown station in downtown Vancouver.
There were no seats, so she grabbed a pole in the middle of the train, said transit police spokeswoman Anne Drennan.
"She suddenly felt some physical contact from behind her, between her legs, and looked down and saw a man's hand groping her with some force," said Drennan.
At the next stop, Vancouver City Centre, the woman got off the train and yelled at the man to leave with her, where she reported the incident to a Canada Line attendant.
"She was very brave, you know," said Drennan.
"She obviously was really confident enough to take action and did so. And fortunately, he did get off the train with her."
This incident is separate from two other sexual assaults reported in the past week on public transit in Metro Vancouver, including one with a Facebook search for the victim.
There have been no developments in those investigations, said Drennan.
Drennan said Goffing has a history of sexual offenses in Germany.
He will be held in custody until he can post a $5000 cash bond or his next scheduled court appearance on March 16 — which is one day after he was scheduled to return to Germany.