Maurice B. Brennan (April 6, 1842 – August 7, 1927) was an Irish American immigrant, politician and farmer.
Born in County Kerry, Ireland, Brennan emigrated with his parents to the United States in 1848, initially settling in Springfield, Massachusetts.
In 1852, Brennan and his family settled in the town of Morrison, Brown County, Wisconsin.
In 1881 and 1905, Brennan served in the Wisconsin State Assembly as a Republican.
Brennan died at the home of his daughter in Cato, Manitowoc County, Wisconsin, where he had been living.