Thomas Marshall Howe (April 20, 1808 – July 20, 1877) was a Whig member of the U.S. House of Representatives from Pennsylvania.

Howe (father-in-law of James W. Brown and George Wilkins Guthrie) was born in Williamstown, Vermont.

He moved to Pittsburgh, Pennsylvania in 1829, where he served as a clerk in a wholesale dry-goods establishment before commencing business for himself in 1833.

He resumed his former business pursuits, and was a delegate to the 1860 Republican National Convention that nominated Abraham Lincoln as the candidate for president.

He was assistant adjutant general on the staff of Governor Andrew Gregg Curtin and chairman of the Allegheny County committee for recruiting Union soldiers during the American Civil War.

Mason and McDonough, Drygoods merchants, corner Third Avenue and Wood Street, Pittsburgh, 1829, Clerk.

S. Baird & Company, Drygoods merchants, corner Fifth Avenue and Wood Street, Pittsburgh, 1831, Salesman.

Pittsburgh & Boston Mining Company, Director and Treasurer for 25 years; original shareholder together with Dr. C. G. Hussey, Wm.