The 1966 Minnesota Secretary of State election was held on 8 November 1966 in order to elect the Secretary of State of Minnesota. Democratic–Farmer–Labor nominee and incumbent Secretary of State Joseph L. Donovan defeated Republican nominee and incumbent member of the Minnesota House of Representatives for the 45th District William J. O'Brien.
General election.
On election day, 8 November 1966, Democratic–Farmer–Labor nominee Joseph L. Donovan won re-election by a margin of 127,359 votes against his opponent Republican nominee William J. O'Brien, thereby retaining Democratic–Farmer–Labor control over the office of Secretary of State. Donovan was sworn in for his sixth term on 2 January 1967.
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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