The 1851 New South Wales colonial election, was held between 12 and 25 September. It involved a re-distribution of electorates as a result of the separation of Victoria, which had 6 seats in the previous council, and the expansion of the council from 24 elected members to 36 elected members representing 31 electorates. The major changes were the addition of 8 pastoral districts and the separate representation for the northern regions of what would later become Queensland. These had previously been a part of the single district of Gloucester, Macquarie, and Stanley and from 1851 were covered by the separate districts of Stanley, Stanley Boroughs and the pastoral districts of Moreton, Wide Bay, Burnett, and Maranoa. The other 8 additional seats were distributed among the nineteen counties of New South Wales.

In 14 out of 31 districts the candidate was elected unopposed, including all eight pastoral districts, which were seen as representing the interests of squatters.^[1]

In 1856 the unicameral Legislative Council was abolished and replaced with an elected Legislative Assembly and an appointed Legislative Council.

There would not be another general election for the Legislative Council until 1978.