Mason Weare Tappan (October 20, 1817 – October 25, 1886) was a New Hampshire state representative, a U.S. congressman from 1855 to 1861, a colonel during the American Civil War and the New Hampshire Attorney General.

He studied law and was admitted to the bar in 1841 and commenced practice in Bradford.

During the Civil War, he served as colonel of the 1st New Hampshire Infantry, a three-months regiment raised in 1861 in response to President Abraham Lincoln's call to arms.

Tappan died in office as the New Hampshire Attorney General at the age of 69.

He is buried in Pleasant Hill Cemetery, Bradford, New Hampshire.