Diane Barz

Diane MacDonald Barz (August 18, 1943 – May 14, 2014) was an American judge. In 1978, she became the first female Montana District Court judge. She was also the first woman to serve as a member of the Montana Supreme Court, a position she held from September 1989 to 1991. She also served as an assistant United States attorney from 1991 to 1994. She then became a law clerk in the Montana Supreme Court. After clerking, she became a deputy county attorney. Then in 1978 she became the first woman elected as a Montana District Court judge, as well as the youngest elected. She was reelected four times to this position. She also served as public defender for Yellowstone County, Montana.

In 1989, Governor Stan Stephens appointed Barz as an associate justice of the Montana Supreme Court. In 1990, Barz resigned from the court rather than participate in a contested statewide election, which she was diagnosed with eight years earlier.