It happened in the area of Birchmount Road and St. Clair Avenue East on Tuesday afternoon.
Toronto police said a woman was sitting on a park bench when she was approached by a boy riding a bicycle.
The boy engaged the woman in a conversation and then allegedly sexually assaulted her.
Police said the boy fled on his bike and was last seen heading towards the intersection of Birchmount Road and St. Clair Avenue East.
The boy is described as five-foot-four with a slim build, short brown hair and one front tooth shorter than the other. He was wearing a red t-shirt and black shorts.
“Investigators believe this is the same suspect from a previous sexual assault alert,” police said in a news release Friday.
Officers have been searching for a teenage boy they believe is responsible for four sexual assaults on Scarborough footpaths in July.
The first two sexual assaults occurred on the afternoons of July 7 and 8 on the Gatineau Hydro Corridor Trail.
In both incidents, the suspect stopped a woman walking along the trail on his bicycle and allegedly sexually assaulted them.
Two more incidents occurred on the East Don Valley Trail near Wynford Drive and Sloane Avenue, where on July 22, the boy asked a woman walking on the trail for water and then sexually assaulted her.
The next day, on the same trail, the suspect allegedly attacked another woman from behind.
While police cannot identify young offenders under the terms of the Youth Criminal Justice Act, police were granted judicial authorization and made the rare move of releasing surveillance images of the boy over a period of time.
Police are asking anyone with information on the suspect’s identity to contact investigators at 416-808-4100 or Crime Stoppers anonymously at 416-222-TIPS (8477).