The government had forwarded the Mounties a report by the auditor general that was highly critical of Redford and her office.
Auditor Merwan Saher said in the report last summer that he found examples of inappropriate spending on government planes and travel. He concluded that Redford and her office used public resources for personal and partisan purposes.
He blamed an "aura of power" that created a perception that their influence should not be questioned.
"In the interest of thoroughness, the RCMP interviewed a wide range of individuals who provided us with information related to the auditor general's report," RCMP Assistant Commissioner Marlin Degrand said in a release Friday. "We thank them for their co-operation, and the file is now concluded."
Jessica Jacobs-Mino, press secretary for Justice Minister Jonathan Dennis, said in an email: "The legal opinion we received recommended we refer this matter to the RCMP. We did that. We are pleased to see it is now concluded."
Redford issued a statement late Friday saying she was grateful it was all over.
"I was never concerned about the outcome, as I had the benefit of knowing that my and my office's actions were above board," she said.
She thanked the RCMP for "very thorough work that leaves no lingering questions."
"Now that this is over I am looking forward to again making a contribution to the province, and country I love."
Neither Premier Jim Prentice nor the RCMP offered further comment.
Redford resigned as premier last March as a caucus revolt brewed over her leadership style and lavish spending.
Just before Saher released his report in August, she resigned her seat as a Calgary backbencher for the Progressive Conservatives, and in a letter acknowledged mistakes were made during her time in office.
"In hindsight, there were many things I would have done differently. That said, I accept responsibility for all the decisions I have made," she wrote, adding she would not comment further.
On Friday, Stefan Baranski, who was Redford's one-time communications director and member of her inner circle, tweeted: "Finally sanity prevails!"
Saher outlined various misdeeds in his report, including a practice of "block booking'' government aircraft to give the appearance that planes were full "so that other passengers could not ride on the same flight'' with the premier and her staff.
Saher said Redford and her former chief of staff denied any knowledge of the practice, but that it was clear the idea came from her office.
Redford also used government planes to attend Progressive Conservative Party of Alberta functions, the auditor said, sometimes scheduling government-related activities for the same times.
On two occasions, she used the planes for trips that Saher found were more personal than business-related: a family funeral in Vancouver and a weekend in Jasper. Her daughter travelled on both occasions, as well as on 48 other flights — a few times with friends and a couple of times without her mother.
Saher called the flights for her daughter a "personal benefit.''
Saher also delved into a trade mission to India and Switzerland that the government said cost $131,000. Adding other fees, such as advance planning, security and travel for other staff, Saher found the trip actually cost $450,000.
He further found that Redford was involved in a plan to add a lavish penthouse premier's suite to a government building under renovation near the legislature. The plan was cancelled, but not before $173,000 was spent on design work.
Wildrose critic Drew Barnes said the flights controversy and all of the Redford-era spending speak to the broader issue of responsibility.
"This is a reminder to the voters of Alberta to hold parties and people responsible (who) don't take good care and provide value for their tax dollars," said Barnes.
NDP Leader Rachel Notley said it doesn't matter that charges have not been laid.
"This is about right and wrong and it's clear the PCs don't know the difference."