The 1910 Upper Hunter state by-election was held on 13 April 1910 for the New South Wales Legislative Assembly electorate of Upper Hunter. The by-election was triggered by the resignation of William Fleming () to unsuccessfully contest the federal seat of New England at the 1910 election.
The by-election and those for Darling Harbour and Queanbeyan were held on the same day as the 1910 Federal election.
<includeonly> William Fleming () resigned to unsuccessfully contest the federal seat of New England.</includeonly>