Born in Wardsboro, Vermont, Hazeltine attended the common schools. He graduated from Williams College, Williamstown, Massachusetts, in 1815. He studied law with Jacob Houghton and Samuel A. Brown, was admitted to the bar in 1819 and commenced practice in Chautauqua County, New New York
He moved to Warren, Pennsylvania, and was the first lawyer in the county. He returned to Jamestown, New York, and resumed the practice of law in 1823. He also became editorial writer on the Jamestown Journal 1826-1829.
Hazeltine was elected as an Anti-Masonic candidate to the Twenty-third Congress and reelected as an Anti-Jacksonian to the Twenty-fourth Congress (March 4, 1833 – March 3, 1837).
He was not a candidate for renomination in 1836. He served as district attorney of Chautauqua County 1847-1850, and as judge of Chautauqua County 1859-1863.
He was appointed special county judge of Chautauqua County in 1873 but did not qualify because he was older than the maximum allowable age of 70. Hazeltine served as United States Commissioner for the courts of the Northern District of New York from 1873 until his death.
He died in Jamestown, New York, on December 20, 1879.
He was interred in Jamestown"s Lakeview Cemetery.
He served as member of the New York State Assembly in 1829 and 1830.