The two candidates were liberal Milwaukee County Judge Janet Protasiewicz and conservative former state Supreme Court justice Daniel Kelly.
Protasiewicz won the election with 55% of the vote. The victory gives Democrats a 4-3 majority on the Wisconsin Supreme Court.
This is the first time Democrats have controlled the court since 2008.
The victory is a major setback for Republicans, who had been hoping to retain control of the court and use it to block Democratic-backed legislation.
The election was seen as a test of the strength of the Democratic Party in Wisconsin.
The results of the election could have implications for future elections in Wisconsin, including the 2024 presidential election.
The Wisconsin Supreme Court is one of the most important courts in the country, as it has the power to decide on a wide range of issues, including abortion rights, gun control, and voting rights.