Sylvester Webster Osborn (July 1, 1811 – November 4, 1903) was a member of the Wisconsin State Assembly.
Osborn was a native of Delaware County, New York.
Among them were Sarah, whose husband Philo A. Orton became a member of the Assembly, and Charles F. Osborn, who was also a member of the Assembly.
During the American Civil War, he served with the 16th Wisconsin Volunteer Infantry Regiment of the Union Army, achieving the rank of captain.
Osborn was a Republican member of the Assembly in 1865.