| Election Name: | 1956 Japanese House of Councillors election |
| Country: | Japan |
| Flag Year: | 1870 |
| Type: | parliamentary |
| Ongoing: | no |
| Previous Election: | 1953 Japanese House of Councillors election |
| Previous Year: | 1953 |
| Next Election: | 1959 Japanese House of Councillors election |
| Next Year: | 1959 |
| Seats For Election: | 127 of the 250 seats in the House of Councillors |
| Majority Seats: | 126 |
| Election Date: | 8 July 1956 |
| Image1: | Hatoyama Ichirō (cropped).jpg |
| Leader1: | Ichirō Hatoyama |
| Party1: | Liberal Democratic Party (Japan) |
| Seats After1: | 122 |
| Seat Change1: | 12 |
| Popular Vote1: | 11,356,874 |
| Percentage1: | 36.7% |
| Swing1: | N/A |
| Leader2: | Mosaburō Suzuki |
| Party2: | Japan Socialist Party |
| Seats After2: | 80 |
| Seat Change2: | 14 |
| Popular Vote2: | 8,549,940 |
| Percentage2: | 29.9% |
| Swing2: | N/A |
| Party4: | Ryokufūkai (1947–1960) |
| Seats After4: | 31 |
| Seat Change4: | 3 |
| Popular Vote4: | 2,877,102 |
| Percentage4: | 10.1% |
| Swing4: | 2.1pp |
| Image5: | Sanzō Nosaka photographed by Shigeru Tamura.jpg |
| Leader5: | Sanzō Nosaka |
| Party5: | Japanese Communist Party |
| Seats After5: | 2 |
| Seat Change5: | 2 |
| Popular Vote5: | 599,254 |
| Percentage5: | 2.1% |
| Swing5: | 1.0pp |
| President of the House of Councillors | |
| Posttitle: | President of the House of Councillors-designate |
| Before Election: | Yūzō Shigemune |
| Before Party: | Liberal Democratic Party (Japan) |
| After Election: | Yutaka Terao |
| After Party: | Liberal Democratic Party (Japan) |
House of Councillors elections were held in Japan on 8 July 1956,[1] electing half the seats in the House plus two vacant seats in the other half. The Liberal Democratic Party won the most seats, but failed to win a majority. It was the first national election under the 1955 System, approximately a two party system of Ichirō Hatoyama's Liberal Democratic Party (LDP) that was created in the "conservative merger" of 1955 and Suzuki Mosaburō's reunified Japan Socialist Party (JSP). The later dominant LDP failed to win a majority.
A key campaign issue was Prime Minister Ichirō Hatoyama's plan to revise Article 9 of the constitution – any change of the constitution requires a two-thirds majority in both chambers of the Diet. The left parties aimed to win at least a third of seats to prevent any constitutional change. Another issue was the government's plan to replace the elected prefectural boards of education with appointed ones, a plan fiercely opposed by the left: In June 1956, on the LDP's request the police intervened in the "deliberations" in the Diet when Socialist Councillors resorted to violence.
Two by-elections for the class of Councillors elected in 1953 were held simultaneously: The candidates with the 51st and 52nd highest vote shares in the national vote (one Socialist and one Liberal Democrat) were elected for three-year terms. Takenaka Tsuneo, who was elected as a member of the Japan Dentists' Federation, later joined the LDP.
| Prefecture | Total seats | Seats won | ||||||
|---|---|---|---|---|---|---|---|---|
| LDP | JSP | Ryokufūkai | JCP | Others | Ind. | |||
| Aichi | 3 | 2 | 1 | |||||
| Akita | 1 | 1 | ||||||
| Aomori | 1 | 1 | ||||||
| Chiba | 2 | 1 | 1 | |||||
| Ehime | 1 | 1 | ||||||
| Fukui | 1 | 1 | ||||||
| Fukuoka | 3 | 1 | 2 | |||||
| Fukushima | 2 | 1 | 1 | |||||
| Gifu | 1 | 1 | ||||||
| Gunma | 2 | 1 | 1 | |||||
| Hiroshima | 2 | 1 | 1 | |||||
| Hokkaido | 4 | 2 | 2 | |||||
| Hyōgo | 3 | 2 | 1 | |||||
| Ibaraki | 2 | 1 | 1 | |||||
| Ishikawa | 1 | 1 | ||||||
| Iwate | 1 | 1 | ||||||
| Kagawa | 1 | 1 | ||||||
| Kagoshima | 2 | 1 | 1 | |||||
| Kanagawa | 2 | 2 | ||||||
| Kōchi | 1 | 1 | ||||||
| Kumamoto | 2 | 1 | 1 | |||||
| Kyoto | 2 | 1 | 1 | |||||
| Mie | 1 | 1 | ||||||
| Miyagi | 1 | 1 | ||||||
| Miyazaki | 1 | 1 | ||||||
| Nagano | 2 | 1 | 1 | |||||
| Nagasaki | 1 | 1 | ||||||
| Nara | 1 | 1 | ||||||
| Niigata | 2 | 1 | 1 | |||||
| Ōita | 1 | 1 | ||||||
| Okayama | 2 | 1 | 1 | |||||
| Osaka | 3 | 1 | 1 | 1 | ||||
| Saga | 1 | 1 | ||||||
| Saitama | 2 | 2 | ||||||
| Shiga | 1 | 1 | ||||||
| Shimane | 1 | 1 | ||||||
| Shizuoka | 2 | 1 | 1 | |||||
| Tochigi | 2 | 1 | 1 | |||||
| Tokushima | 1 | 1 | ||||||
| Tokyo | 4 | 1 | 2 | 1 | ||||
| Tottori | 1 | 1 | ||||||
| Toyama | 1 | 1 | ||||||
| Wakayama | 1 | 1 | ||||||
| Yamagata | 1 | 1 | ||||||
| Yamaguchi | 1 | 1 | ||||||
| Yamanashi | 1 | 1 | ||||||
| National | 52 | 19 | 21 | 5 | 1 | 1 | 5 | |
| Total | 127 | 61 | 49 | 5 | 2 | 1 | 9 | |