The 1859 New South Wales colonial election was for 80 members representing 67 electoral districts. The election was conducted on the basis of a simple majority or first-past-the-post voting system. In this election there were 9 multi-member districts returning 22 members and 58 single member districts. In the multi-member districts each elector could vote for as many candidates as there were vacancies. 15 districts were uncontested.
The electoral districts and boundaries were established under the Electoral Act 1858 (NSW), The changes included an increase in the number of members from 54 to 80 and an increase in the number of districts from 54 to 67, with 62 new districts and only five of the former districts remained. The 62 new districts were based on the established Police districts. The new districts included three districts for people with a mining or business licence in the goldfields, Goldfields North, Goldfields South and Goldfields West, which did not have a residential or property qualification. The average number of enrolled voters per seat in the other districts was 1,394 ranging from The Paterson (536) to The Lachlan (3,592).
Queensland separated from NSW in December 1859 and the 10 members elected for the 9 Queensland seats ceased to sit.
Daniel Egan was defeated as the sitting member for Monara.
John Hargrave was a member for East Camden.
Daniel Egan was elected for Eden.
Four people were charged with impersonating electors and a petition was lodged against the election. The Elections and Qualifications Committee conducted a re-count.
Samuel Gordon was the member for the abolished district of Durham.