William Brabazon, 1st Earl of Meath (c.1580 - 18 December 1651) was an Anglo-Irish peer. Brabazon was descended from an English family that was seated in Leicestershire from the reign of the Henry III, and came to Ireland in the 1530s. He was the second but eldest surviving son of Edward Brabazon and Mary Smythe, daughter of Thomas Smythe, Clerk of the Green Cloth. His father had been created Baron Ardee in 1616. His grandfather, also William Brabazon, had served as Vice-Treasurer of Ireland for 23 years and the family owned large estates there.