Gretchen Whitmer will deliver the Democratic response to President Donald Trump's State of the Union address on Feb. 4.
House Speaker Nancy Pelosi and Senate Democratic Leader Chuck Schumer made the announcement Friday.
They praised Whitmer for her efforts to ensure clean drinking water is available in communities across Michigan, which was scarred by the 2014 water crisis in Flint.
About 25,000 people have sued over the crisis, in which a change in the source of the city's water resulted in lead contamination.
She had previously served as Democratic Leader in the Michigan state Senate and was the first woman to lead the Senate caucus.