Members of the New South Wales Legislative Assembly, 1858–1859

This is a list of members of the New South Wales Legislative Assembly from 1858 to 1859:

¹ Cumberland (North Riding) MLA Henry Parkes resigned on 28 August 1858 due to financial difficulties. The resulting by-election on 20 September 1858 was won by John Plunkett. ² New England and Macleay MLA Abram Moriarty resigned on 13 October 1858. The resulting by-election on 14 December 1858 was won by James Hart. ³ East Camden MLA Robert Owen resigned on 3 March 1859 to take a seat on a District Court. The resulting by-election on 21 March 1859 was won by John Hargrave.

There was no party system in New South Wales politics until 1887. Under the constitution, ministers were required to resign to recontest their seats in a by-election when appointed. These by-elections are only noted when the minister was defeated; in general, he was elected unopposed.