Henry Haslett (1758 – 1806) was in 1791 a founding member in Belfast of the democratic-revolutionary Society of the United Irishmen, and one of the twelve original proprietors of its Painite newspaper, the Northern Star. He had been representative of a group of merchants in the city who had chafed at the Navigation Acts and other measures enacted under the British Crown that restricted Irish trade and industry. He was released from fourteen-months detention just before the Irish Rebellion of 1798 in which he played no role. After the 1800 Acts of Union incorporating Ireland in a United Kingdom with Great Britain, he was again active in the commercial life of Belfast promoting its growth as a port.