Henry Macdermott (1798 – 1 February 1848) was an Irish-born politician and merchant in the colony of New South Wales.
Macdermott was born to a Protestant family in County Roscommon.
Having enlisted in 1820, Macdermott was a sergeant with the 39th Regiment by the time he had arrived in Australia in 1827.
His military career ended in 1831, having achieved the rank of sergeant-major.
He was mayor in 1845, before resigning from council in August 1847 due to bankruptcy.