McMillan Township is a civil township of Ontonagon County in the U.S. state of Michigan. The population was 406 at the 2020 census.

According to the United States Census Bureau, the township has a total area of 70.50 square miles (182.59 km), of which 70.43 square miles (182.41 km) is land and 0.07 square miles (0.18 km) (0.10%) is water.

• Ewen is an unincorporated community and census-designated place at 46°32′07″N 89°16′52″W / 46.53528°N 89.28111°W / 46.53528; -89.28111, near where M-28 crosses the south branch of the Ontonagon River. The community began as a logging camp in 1888 and in 1889 gained a depot named Ewen Station on the Duluth, South Shore and Atlantic Railway (now the Soo Line Railroad). It was named for W. A. Ewen, a treasurer of the railroad. It also received a Post Office named Ewen Station in 1889, shortened to Ewen in 1894. The Ewen Post Office, ZIP code 49925, serves much of the township area. Bruce Crossing is about 5 miles east on M-28 and Matchwood about 6 miles west.