John Blennerhassett (1769 – 6 July 1794) was an Anglo-Irish politician.
Blennerhassett was the son of William Blennerhassett and Catherine Johnson, and the great-grandson of John Blennerhassett.
He was educated at Trinity College Dublin, graduating with a master's in 1792.
Between 1790 and his death in 1794 Blennerhassett sat in the Irish House of Commons as the Member of Parliament for County Kerry.
[1] He was unmarried when he died.