Mason Brayman (May 23, 1813 – February 27, 1895) was an American attorney, newspaperman, and military officer. During his service to the Union Army during the American Civil War, he rose to the rank of major general with the 29th Illinois Volunteer Infantry. Later in life, he became the seventh governor of the Idaho Territory.

Brayman was born in Buffalo, New York on May 23, 1813. Raised with a Calvinist outlook and a hatred of liquor, he was apprenticed to a printer at the age of 17. Five years later, he became editor of a local newspaper. In addition to his work with newspapers, he studied law and was admitted to the New York Bar in 1836.

The year after his admission to the bar, Brayman married a woman named Mary. She was a direct descendant of Roger Williams, and they had two daughters and a son. Following his marriage, Brayman began a series of westward moves, working as a city attorney in Michigan and newspaper editor in Ohio, before settling in Springfield, Illinois, during the early 1840s.

In Springfield, Brayman practiced law with Jesse B. Thomas Jr., and wrote editorials for the town's newspapers. In addition to spending time with persons such as Abraham Lincoln and Stephen A. Douglas, he oversaw the American Baptist Publishing Society, was active in the temperance movement, and was a leader of the local Baptist church.

In 1844, Brayman gained statewide prominence by accepting a commission from Governor Thomas Ford to revise the Illinois legal code. Two years later he was commissioned as a special prosecutor to deal with incidents occurring during the Illinois Mormon War. In this capacity he devised the agreement which allowed the Mormons to leave Illinois.

In the 1850s, Brayman joined the staff of the Illinois Central Railroad, working to gain rights of way for the expanding railroad. In 1855, he sold his position with the Illinois Central and took a position with the Cairo and Fulton Railroad. This move proved to be a financial blunder as the new railroad eventually failed, while the Illinois Central prospered. During 1858, Brayman campaigned for Abraham Lincoln's Illinois senate candidacy.

With the outbreak of the American Civil War, Brayman joined with other railroad executives and secured a military commission. Initially serving as a major with the 29th Illinois Volunteer Infantry Regiment under General McClernand, he was promoted to colonel on April 15, 1862, and command of his regiment. Following the Battle of Fort Donelson, Brayman stopped shaving and grew a beard that would eventually reach his belt. He also had his horse shot out from under him twice. At Shiloh he became a minor hero, rallying his troops by charging between the Union and Confederate lines. During the Siege of Vicksburg he suffered a bout of heatstroke that forced him into garrison duty. By the end of the war, he had achieved the rank of Major General and was serving as head of a claims commission in New Orleans. Major General Mason Brayman was the highest-ranking Civil War officer to have lived in the Lincoln's neighborhood. Mason Brayman – 42 years old, served as a Major General with the 29th IL Volunteer Infantry. He lived in the neighborhood two times—once as a renter in the Lincoln Home and once as a renter in what is now called the Shutt House.

Following the war, Brayman attempted to revive his career with the Cairo and Fulton before returning to work as a newspaper editor in Springfield and Quincy, Illinois. In 1873, he entered semi-retirement on a farm in Ripon, Wisconsin; however, the Panic of 1873 destroyed most of his wealth, and by 1876 he was lobbying for a patronage appointment.