Robert Marshall Briggs (February 15, 1816 – December 8, 1886) was an American merchant, lawyer, judge and politician in Wisconsin and California. Briggs served as a Whig member of the 2nd and 4th Wisconsin Legislatures representing Grant County in the Wisconsin State Assembly;[1] and in 1857 was elected to the California State Assembly from Amador County as a Know-Nothing. He also served as a district attorney and a judge.