The latest such robbery happened Sunday night at Chester Station on the Bloor-Danforth line.
At about 10:30 p.m. a man walked into the station armed with a handgun.
He stole an undisclosed amount of money from the fare collector and fled the scene.
The fare collector was not injured. Toronto police have no suspect description.
Sunday’s incident is similar to an Aug. 6 robbery, also at Chester Station, in which a man wearing a black hooded sweatshirt and a bandana over his face pointed a gun at the fare collector and stole cash and Metropasses.
Later in August — on the 26th — Toronto Police believe the man involved in the Aug. 6 robbery used a handgun to rob a fare collector at Christie Station.
Police describe him as white, 25 to 30 years old, around six feet tall.
It’s unclear whether Sunday night’s robbery is connected to the two that happened in August.
In February 2012, a TTC fare collector was shot at Dupont station.
The worker was hit twice but survived.
The shooting remains unsolved and the TTC has posted a $25,000 reward for information about that shooting.