A by-election was held for the New South Wales Legislative Assembly electorate of Lismore on 12 September 1959 because Justice Sugerman in the Court of Disputed Returns declared that the 1959 Lismore election was void. Electoral officers failed to initial or sign 51 ballot papers, rendering those papers informal. Those electors had been prevented from casting an effective vote and therefore preventing from voting. As Jack Easter's margin at the election was only 2 votes, the errors may have affected the result of the election.^[1]

• Clyde Campbell, was an independent candidate at the 1959 election but was endorsed by the Country Party for the by-election
• Jack Easter was the sitting member and retained Country Party endorsement. He had been elected with 63% of the two-party-preferred result at the 1953 Lismore election, increasing to 68% at the 1956 Lismore election.^[5]
• Keith Compton was the Labor candidate. There had been no Labor candidate at the election in March.

• Electoral results for the district of Lismore
• List of New South Wales state by-elections