The 1940 Missouri Secretary of State election was held on 5 November 1940 in order to elect the secretary of state of Missouri. Democratic nominee and incumbent secretary of state Dwight H. Brown defeated Republican nominee Loyd Miller, Socialist nominee Henry Siroky and Socialist Labor nominee Henry W. Genck.
General election.
On election day, 5 November 1940, Democratic nominee Dwight H. Brown won re-election by a margin of 109,661 votes against his foremost opponent Republican nominee Loyd Miller, thereby retaining Democratic control over the office of secretary of state. Brown was sworn in for his third term on 13 January 1941.
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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