The 1889 Oamaru by-election was a by-election held on 30 September 1889 in the electorate during the 10th New Zealand Parliament.
The by-election was caused by the resignation of the incumbent MP Thomas William Hislop. Hislop was returned as the MP. He was opposed by Mr D. Dunn.[1]
Hislop's majority was reduced from 136 to 134 after two votes were removed.[2] One person was charged with voting twice (personation).[3]
The following table gives the election result: