The 1873 Waikouaiti by-election was a by-election held on 23 July 1873 in the Waikouaiti electorate during the 5th New Zealand Parliament.
The by-election was caused by the resignation of the incumbent MP David Monro.
Candidates for the by-election were John Lillie Gillies, Thomas Slater Pratt, and John Graham.[1] Pratt had been mayor of Waikouaiti since July 1870.[2] Gillies was Speaker of the Provincial Council at the time.[3]
The by-election was won by Gillies.