It's alleged the Bendale Business and Technical Institute teacher had a sexual relationship with a female student under the age of 18.
Police believe there may be more alleged victims.
Thirty-nine-year-old Matthew Elms was arrested Friday and charged with one count of sexual exploitation.
They say he has since been released on bail with conditions forbidding him from being in a position of trust or authority to anyone under the age of 18.
He's due in court next month.
Police say Elms has been a teacher with the Toronto District School Board since 2000 and has also taught at Martingrove Collegiate Institute, another Toronto school.