1966 Finnish Parliamentary Election

The Social Democratic Party (SDP) overtook the Centre Party as the largest faction in Parliament. Rafael Paasio of the SDP subsequently became Prime Minister and formed a popular front government consisting of the SDP, the Centre Party, the People's Democratic League (SKDL), and the Social Democratic Union of Workers and Smallholders (TPSL) in May 1966.

1966 Finnish parliamentary election

← 1962 20–21 March 1966 1970 →
All 200 seats in the Parliament of Finland 101 seats needed for a majority
First party Second party Third party   Leader Rafael Paasio Johannes Virolainen Kusti Kulo Party SDP Centre SKDL Last election 19.50%, 38 seats 22.95%, 53 seats 22.02%, 47 seats Seats won 55 49 41 Seat change 17 4 6 Popular vote 645,339 503,047 502,374 Percentage 27.23% 21.23% 21.20% Swing 7.73pp 1.72pp 0.82pp   Fourth party Fifth party Sixth party   Leader Juha Rihtniemi Lars Erik Taxell Mikko Juva Party National Coalition RKP Liberal People's Last election 15.06%, 32 seats 6.11%, 13 seats 6.86%, 14 seats Seats won 26 11 9 Seat change 6 2 5 Popular vote 326,928 134,831 153,259 Percentage 13.79% 5.69% 6.47% Swing 1.27pp 0.42pp 0.39p   Seventh party Eighth party Ninth party   Leader Aarre Simonen Veikko Vennamo Party TPSL Smallholders' Party ÅS Last election 4.36%, 2 seats 2.16%, 0 seats 0.32%, 1 seat Seats won 7 1 1 Seat change 5 1 Popular vote 61,274 24,351 7,118 Percentage 2.59% 1.03% 0.30% Swing 1.77pp 1.13pp 0.02pp
Prime Minister before election Johannes Virolainen Centre Prime Minister after election Rafael Paasio SDP

Prior to the elections, Centre Party Prime Minister Johannes Virolainen had led a centre-right coalition government since September 1964. Meanwhile, Paasio had moved the SDP further to the left in order to attract back voters from the TPSL. Finnish society was undergoing a period of radical criticism of traditional values, such as Christianity, marriage, parents' authority over their children, teachers' authority over their students, patriotism, and civil servants' (including judges') authority over private citizens. The Social Democrats and the SKDL tapped into this discontent at the expense of the centre-right coalition. At the same time, leading Social Democrats, such as former Minister of Social Affairs and Minister of the Interior Väinö Leskinen, had promised to support President Kekkonen's foreign policy with regards to the Soviet Union, and his continuance as President.

Overall, the leftist coalition achieved a combined majority (51.0%) of the votes cast in the election.

Party		Votes	%	Seats	+/–
	Social Democratic Party	645,339	27.23	55	+17
	Centre Party	503,047	21.23	49	–4
	Finnish People's Democratic League	502,374	21.20	41	–6
	National Coalition Party	326,928	13.79	26	–6
	Liberal People's Party	153,259	6.47	9	–5
	Swedish People's Party	134,831	5.69	11	–2
	Social Democratic Union of Workers and Smallholders	61,274	2.59	7	+5
	Smallholders' Party	24,351	1.03	1	+1
	Finnish Christian League	10,646	0.45	0	New
	Åland Coalition	7,118	0.30	1	0
	Independence Party	513	0.02	0	New
	Christian Women of Western Finland	124	0.01	0	New
	Christian-minded of Northern Savonia	30	0.00	0	New
	Others	51	0.00	0	–
	Write-ins	161	0.01	0	–
Total		2,370,046	100.00	200	0
Valid votes		2,370,046	99.64
Invalid/blank votes		8,537	0.36
Total votes		2,378,583	100.00
Registered voters/turnout		2,800,461	84.94
Source: Tilastokeskus 2004

By electoral district