William M. Blair (born May 25, 1836 – 1919) was a farmer and political figure in Nova Scotia, Canada. He represented Colchester County in the Nova Scotia House of Assembly from 1878 to 1886 as a Liberal-Conservative member.
(December 6, 1834 March 14, 1920) was a United States Representative and Senator from New Hampshire. Born in Campton, he attended the common schools and private academies, studied law, was admitted to the bar in 1859 and commenced practice in Plymouth. He was appointed prosecuting attorney for Grafton County in 1860, and during the Civil War he served in the Union Army as lieutenant colonel of the Fifteenth Regiment, New Hampshire Volunteer Infantry.