Jacobus Severyn Bruyn (April 7, 1749 – May 25, 1823) was an American politician from Ulster County, New York.
He was a son of Jacobus Bruyn and Jane (née Graham) Pruyn (d. 1764).
[1] In April 1797, Bruyn was elected to succeed his brother Johannes as a Democratic-Republican New York Assemblymen from Ulster County in the 21st and 22nd New York State Legislatures from July 1, 1797, until June 30, 1799.
His seat was one of the 12 representing the Middle District which then consisted of Dutchess, Orange, Ulster, Columbia, Delaware, Rockland and Greene counties.
In April 1801, Bruyn was reelected to a four-year term, serving in the 25th, 26th, 27th and 28th New York State Legislatures until June 30, 1805.