The apology, thought to be the first by a Canadian province, is directed at individuals from the so-called '60s Scoop, which many see as an extension of Indian residential schools policy.
Premier Greg Selinger said the apology, expected next week in the legislature, will acknowledge damage done to those taken from their homes and their culture. Manitoba was one of the provinces most affected, so it is appropriate that it be among the first to apologize, he said.
"It's an acknowledgment that they did lose contact with their families, their language, their culture," Selinger told The Canadian Press. "That was an important loss in their life and it needs to be acknowledged. It's part of the healing process."
Adoptees have been calling for a federal apology and many want compensation for their experience, which they say was as traumatic as that suffered by residential school survivors.
Selinger said he hopes the apology prompts the federal government to say it's sorry.
"These policies were initiated at the federal level all across the country. We're acknowledging the harms done in Manitoba and the need for healing in Manitoba. We'd like to see the federal government address it on a pan-Canadian level as well."
From the 1960s to the 1980s, thousands of aboriginal children were taken from their homes by child-welfare services and placed with non-aboriginal families, some in the United States.
Manitoba has organized gatherings of adoptees to share their stories and helped bring the idea of compensation, counselling and repatriation to premiers last year.
Residential school survivors have had a formal apology from Ottawa and were able to speak at hearings held by the Truth and Reconciliation Commission, which released its summary final report last week. But '60s Scoop adoptees haven't been formally recognized.
Coleen Rajotte was taken from her Cree community in Saskatchewan when she was three months old and raised by a Manitoba family. The apology means a lot, but it's just the beginning, she said.
Adoptees deserve a national commission of their own, Rajotte said. Some adoptees have never made it home and can't be repatriated because they can't prove they are Canadian.
"A huge effort has to be made to reach out and find all the kids who haven't come back yet," said Rajotte, who has spoken before the United Nations.
David Chartrand was taken from his Manitoba family when he was five and moved to Minnesota, where he said he was placed with a family that treated him like a "slave" and a "punching bag."
When he returned to his home community of Camperville, Man., in his 20s, he said he had nothing. An apology is the least a government can do for those who feel like "forgotten people," he suggested.
"It brings recognition that there was an injustice done to us. I was hoping this would be the federal government that would do this."
Chartrand, like many other adoptees, is seeking justice through a class-action lawsuit filed in Saskatchewan, Manitoba and Alberta. Another class-action lawsuit in Ontario is still making its way through the courts.
"I'll see them in court," Chartrand said. "If the Queen herself was to say, 'I'm sorry for what they did to you,' I would accept that."
Tony Merchant, a Regina lawyer representing adoptees including Chartrand, said the government's apology is important. But if Manitoba were serious about reconciliation, it could follow the apology with a compensation package, he said.
"The first step always is to recognize wrong and then consider what ought to be done."
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