The Blennerhassett Baronetcy of Blennerville in the County of Kerry, is a title in the Baronetage of the United Kingdom. It was created on 22 September 1809 for Rowland Blennerhassett, the member of a family that was originally settled in Cumberland, England, and subsequently at Frenze, Norfolk, and Barsham, Suffolk. Members of the Blennerhassett family represented Carlisle in almost every Parliament from the reign of Richard II to the reign of James I. This branch of the family settled in County Kerry during the reign of James I and its members frequently represented County Kerry and Tralee in the Irish House of Commons. The first Baronet's son, the second Baronet, was High Sheriff of Kerry in 1823. He was succeeded by his son, the third Baronet. He served as High Sheriff of County Kerry in 1820. His son, the fourth Baronet, was a Liberal politician. As of 2008 the title is held by the latter's great-grandson (the baronetcy having descended from father to son), the seventh Baronet, who succeeded in 1940.
Rowland Blennerhassett, grandson of Rowland Blennerhassett, fourth son of the first Baronet, represented County Kerry in the House of Commons.