Person was born on a farm near Howell, Michigan and attended the district schools and the Howell public schools. He graduated from the law department of the University of Michigan at Ann Arbor in 1901. He was admitted to the bar the same year and commenced practice in Lansing and was a law partner with Patrick H. Kelley.
Person served as a member of the Michigan House of Representatives (Ingham County 1st district) from 1915 to 1921 and also served in the Michigan Senate (27th district) from 1927 to 1931. He was a delegate to all State conventions for thirty years.
In 1930 Republican Party primary elections, Person defeated the incumbent U.S. Representative Grant M. Hudson. Person went on to win the general election to represent Michigan's 6th congressional district in the 72nd United States Congress, serving from March 4, 1931 to March 3, 1933. He was an unsuccessful candidate for reelection in 1932, losing to Democrat Claude E. Cady. He also unsuccessfully challenged incumbent William W. Blackney in the Republican primary election of 1942. Seymour H. Person resumed the practice of his profession after leaving Congress. He died in Lansing and is interred in Deepdale Cemetery.