Dave Hancock was sworn in Sunday as Alberta premier following the resignation of Redford. Hancock served as Redford's deputy.
Harper issued a statement from the sidelines of an economic summit in the Netherlands praising Redford for her leadership.
"Redford was a strong steward of the Alberta economy, " he said Sunday.
Redford last year accompanied the prime minister on a visit to the United States to make the case for the passage of the Keystone XL oil pipeline from Alberta. Harper's administration has touted the pipeline as a way to ensure North American energy security.
Canadian pipeline company TransCanada needs a permit from the U.S. federal government to build the cross-border pipeline. Opponents say the heavier grade of crude oil found in Alberta is a greater threat to the environment than conventional oil.
Redford announced her resignation last week amid a row over travel expenses. She said last week she had "profound optimism" for Alberta's future.