Colleen O'Brian is an Oakland County Circuit judge who ran with the Republican endorsement for the Michigan Supreme Court in 2012. She lost in the general election.
O'Brian has a bachelor's degree from the University of Michigan and a law degree from the Detroit College of Law. She became a judge of the 6th Circuit, that covers Oakland County, in 1998.
After Diane Hathaway resigned from the Michigan Supreme Court amid fraud charges O'Brien was seen as a strong candidate to replace her. The appointment eventually went to David Viviano of Macomb County.