The Newcomen Baronetcy, of Kenagh in the County of Longford, was a title in the Baronetage of Ireland.
Born in London, the third son of Charles Newcomen and Jane Nightingale, Robert had come to Ireland in the late sixteenth century.
He settled at Keenagh in County Longford, where he became a substantial landowner, and sat in the Irish House of Commons for Kilbeggan.
The sixth, seventh and eighth Baronets also represented County Longford in the Irish House of Commons.
She was married to William Gleadowe, who assumed the additional surname of Newcomen at the time of their marriage and was created a baronet in 1781.