Supreme Soviet elections were held in the Soviet Union on 12 June 1966.^[1]

Candidates had to be nominated by the Communist Party of the Soviet Union (CPSU) or by a public organisation.^[2] However, all public organisations were controlled by the party and were subservient to a 1931 law that required them to accept party rule.^[2] The CPSU itself remained the only legal one in the country.^[3]

Voters could vote against the CPSU candidate if they wished, but could only do so by using polling booths, whereas votes for the party could be cast simply by submitting a blank ballot.^[2] Turnout was required to be over 50% for the election to be valid.^[2]

CPSU candidates accounted for around three quarters of the nominees, whilst many of the others were members of Komsomol.^[4]

Party		Votes	%	Seats	+/–
	Communist Party of the Soviet Union	143,570,976	99.76	573	–31
	Independents			194	+7
Against		345,643	0.24	–	–
Total		143,916,619	100.00	767	–24
Valid votes		143,916,619	100.00
Invalid/blank votes		412	0.00
Total votes		143,917,031	100.00
Registered voters/turnout		144,000,973	99.94
Source: Nohlen & Stöver

Party		Votes	%	Seats	+/–
	Communist Party of the Soviet Union	143,595,678	99.78	568	+78
	Independents			182	+20
Against		320,972	0.22	–	–
Total		143,916,650	100.00	750	+98
Valid votes		143,916,650	100.00
Invalid/blank votes		381	0.00
Total votes		143,917,031	100.00
Registered voters/turnout		144,000,973	99.94
Source: Nohlen & Stöver