"We want the First Nation, Metis and Inuit people of Alberta to know that we deeply regret the profound harm and damage that occurred to generations of children forced to attend residential schools," said Notley in a speech to the house.
"Although the province did not establish this system, members of this chamber at the time did not take a stand against it.
"And for this silence, we apologize."
In the gallery watching the speech were a number of invited guests of the premier, including residential school survivors.
Earlier this month, the national Truth and Reconciliation Commission detailed more than a century of institutionalized abuse of generations of aboriginal children in residential schools.
The report, based on interviews with thousands of survivors, detailed the plight of youngsters forcibly separated from their families to endure loneliness, cruelty and physical and mental abuse tantamount to "cultural genocide."
The commission estimated more than 6,000 children, about one in 25, died in the residential schools, the last of which didn't close until 1996.
The report made 94 recommendations to repair the bonds between the country and its founding peoples, including that Canada adopt and implement the United Nations Declaration on the Rights of Indigenous Peoples as the framework for reconciliation.
"This past is too painful to endure on your own," Notley told the survivors.
"In the journey of reconciliation you no longer have to walk alone."
Notley also urged the federal government to convene an inquiry on missing and murdered aboriginal women.
Numerous provincial, national and international organizations, including a committee of the United Nations, have been calling for such an inquiry to shed light on the root causes for the disproportionately high number of indigenous women who are missing or have been murdered.
"With full conviction, we lend our voice and our conscience to doing right by the women, their families and their communities," said Notley.
"The silence that once was, has long since passed."
Last week, the RCMP reported that since 1980, there have been 1,049 murdered aboriginal women and another 175 have disappeared.
Police said most of the time, the women were killed by family members or men they knew.
Prime Minister Stephen Harper's government has resisted calls for an inquiry, saying more study is not needed and that steps are being taken to remedy the problems.
Opposition Wildrose Leader Brian Jean applauded Notley's statement but said she needs to go further.
He said rather than just ask the federal government for action, she could act now by spending more money to improve standards for aboriginal children in care, adding funds to address fetal alcohol disorders, or deliver more cash for the RCMP to investigate missing persons.
"Hopefully in the future we will see provincial action rather than a speech calling for action from the federal government," said Jean.
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