John Browne, 1st Earl of Altamont (c. 1709 – 4 July 1776), styled Lord Mount Eagle between 1760 and 1768 and Viscount Westport between 1768 and 1771, was an Irish peer and politician.

He was a grandson of Colonel John Browne, a signatory of the Treaty of Limerick, and of Denis Daly, judge of the Court of Common Pleas (Ireland).

In 1771 he was even further honoured when he was made Earl of Altamont, in the County of Mayo.

He also did much to improve the linen trade in the town of Westport, County Mayo.

He also extensively rebuilt Westport House, which remained the family home until 2017.