The 1870 Mongonui by-election was a by-election held on 30 March 1870 in the Mongonui electorate during the 4th New Zealand Parliament.
The by-election was caused by the resignation of the incumbent MP Thomas Ball on 1 March 1870.
[1] The by-election was won by Thomas Gillies.
The following table gives the election result:
This New Zealand election-related article is a stub.