The 1920 Missouri State Auditor election was held on 2 November 1920 in order to elect the state auditor of Missouri. Republican nominee and incumbent state auditor George Ernst Hackman defeated Democratic nominee and incumbent State Treasurer of Missouri George H. Middelkamp, Socialist nominee Roy F. Smalley, Farmer-Worker nominee A. R. Smith and Socialist Labor nominee Frederick Spalti.
General election.
On election day, 2 November 1920, Republican nominee George Ernst Hackman won re-election by a margin of 154,885 votes against his foremost opponent Democratic nominee George H. Middelkamp, thereby gaining Republican control over the office of state auditor. Hackman was sworn in for his second term on 10 January 1921.
Results.
! scope="col" colspan="2" style="width: 15em" |Party
! scope="col" style="width: 17em" |Candidate
! scope="col" style="width: 5em" |Votes
! scope="col" style="width: 3.5em" |%
! colspan="3" style="text-align:right;" | Total votes
References.
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