Martin Alonzo Haynes (July 30, 1842 – November 28, 1919) was an American politician and a United States Representative from New Hampshire.

At the outbreak of the Civil War, he enlisted in June 1861 in the Union Army as a private in the Second New Hampshire Regiment and served three years.

Haynes moved to Lakeport, Belknap County, New Hampshire in 1868, where he established the Lake Village Times, published every Saturday.

He was president of the New Hampshire Veterans' Association in 1881 and 1882, and was department commander of the Grand Army of the Republic in 1881 and 1882.

[2] This article incorporates public domain material from the Biographical Directory of the United States Congress