The ceremony was held to add the names of 18 firefighters to the Ontario Firefighters Memorial outside the provincial legislature.
There are now 574 names on the memorial, which depicts a firefighter carrying a child to safety.
Premier Dalton McGuinty says the men "paid the ultimate sacrifice" by trying to protect the public.
This year's honourees include firefighters who died from 1969 to 2012 from all across Ontario, including Hamilton, Sarnia, Ottawa and Toronto.
The service also included a performance by a pipe-and-drum band and nearby flags were flown at half mast to remember the dead.
"These names we add today and all the names here, speak to character," said McGuinty.
"These were men who chose public service. They chose to put the needs of others ahead of their own. These names speak to courage. These men confronted danger and took risks not because they were unafraid but because they were made bold by their strong sense of duty."
Ontario Fire Marshal Ted Wieclawek, representatives from various firefighter associations and family members of those honoured were all present for the service.