The Truth and Reconciliation Commission provided cake, glow sticks, songs and cheers Sunday for all of the survivors who were never able to celebrate.
A stage was filled with children the same ages as many who attended the church-run schools.
The government apologized several years ago for the schools, where many aboriginal children were physically, emotionally and sexually abused.
The commission is holding hearings across the country and was in Saskatoon for several days last week.
Some of the people who attended said being able to celebrate a crucial part of childhood such as a birthday with other survivors was inspiring.
"I'm not alone. At residential school, you felt so alone. You thought you were the only one going through this pain," said Bernadette Neapetung.
"Holding this cake ... I don't remember having a birthday."
She attended the hearings with her brother, George, who also was sent to a residential school.
"It's been a lightening of a load that I have carried for the entirety of my life," he said, "To be able to give a voice to that little boy inside of me and to let all of those things go."
He said he was struck by the children on the stage.
"I didn't know how small I really was at that time ... and it brought me back. It touched me where I have never been touched before, where I never allowed anything before."
The brother and sister said that they would walk away from the commission hearings as stronger people.
"I'm walking away with a hope for my children and my grandchildren. I'm proud to be a First Nations woman," said Bernadette Neapetung.
"I'm taking my life ... I'm going to work with that with my grandchildren back home ... I bring some more freedom for them, freedom for choice in their own lives," said her brother.