| Election Name: | 1970 Hessian state election |
| Country: | Hesse |
| Type: | parliamentary |
| Ongoing: | no |
| Previous Election: | 1966 Hessian state election |
| Previous Year: | 1966 |
| Next Election: | 1974 Hessian state election |
| Next Year: | 1974 |
| Seats For Election: | All 110 seats in the Landtag of Hesse |
| Majority Seats: | 56 |
| Election Date: | 8 November 1970 |
| Turnout: | 3,171,227 (82.8% 1.9pp) |
| Candidate1: | Albert Osswald |
| Party1: | Social Democratic Party of Germany |
| Last Election1: | 52 seats, 51.0% |
| Seats1: | 53 |
| Seat Change1: | 1 |
| Popular Vote1: | 1,442,201 |
| Percentage1: | 45.9% |
| Swing1: | 5.1pp |
| Candidate2: | Alfred Dregger |
| Party2: | Christian Democratic Union of Germany |
| Last Election2: | 26 seats, 26.4% |
| Seats2: | 46 |
| Seat Change2: | 20 |
| Popular Vote2: | 1,248,543 |
| Percentage2: | 39.7% |
| Swing2: | 13.4pp |
| Candidate4: | Heinz-Herbert Karry |
| Party4: | Free Democratic Party (Germany) |
| Last Election4: | 10 seats, 10.4% |
| Seats4: | 11 |
| Seat Change4: | 1 |
| Popular Vote4: | 316,270 |
| Percentage4: | 10.1% |
| Swing4: | 0.3pp |
| Party5: | National Democratic Party of Germany |
| Last Election5: | 8 seats, 7.9% |
| Seats5: | 0 |
| Seat Change5: | 8 |
| Popular Vote5: | 94,531 |
| Percentage5: | 3.0% |
| Swing5: | 4.9pp |
| Map Size: | 250px |
| Government | |
| Before Election: | First Osswald cabinet |
| Before Party: | SPD |
| Posttitle: | Government after election |
| After Election: | Second Osswald cabinet |
| After Party: | SPD–FDP |
The 1970 Hessian state election was held on 8 November 1970 to elect the 7th Landtag of Hesse. The outgoing government was a majority of the Social Democratic Party (SPD) led by Minister-President Albert Osswald.
The opposition Christian Democratic Union (CDU), which had taken a hard line against the SPD under new leader Alfred Dregger, recorded a major swing of 13 percentage points in its favour, to the detriment of the SPD and National Democratic Party, the latter losing all its seats after a single term in the Landtag. The SPD remained the largest party with 46%, and subsequently formed a coalition with the Free Democratic Party, following in the footsteps of the federal government formed the previous year.
The Landtag was elected via mixed-member proportional representation. The size of the Landtag was increased in this election from 96 to 110 members. 55 members were elected in single-member constituencies via first-past-the-post voting, and 55 then allocated using compensatory proportional representation. A single ballot was used for both. An electoral threshold of 5% of valid votes is applied to the Landtag; parties that fall below this threshold are ineligible to receive seats.
See main article: 1966 Hessian state election. In the previous election held on 6 November 1966, the SPD retained its majority with 51% of the vote. The CDU and FDP both stagnated on 26% and 10% respectively, while the new right-wing NPD capitalised on discontent over the economy and the major parties and entered the Landtag with 8%. This marked the party's first success in an election and was followed by a string of similar showings in other states over the following two years. In October 1969, long-serving Minister-President Georg-August Zinn resigned after 19 years in office after suffering a severe stroke. He was succeeded by finance minister Albert Osswald.
The table below lists parties represented in the 6th Landtag of Hesse.
| Name | Ideology | Lead candidate | 1966 result | |||||
|---|---|---|---|---|---|---|---|---|
| Votes (%) | Seats | |||||||
| bgcolor= | SPD | Social Democratic Party of Germany | Social democracy | Albert Osswald | 51.0% | |||
| bgcolor= | CDU | Christian Democratic Union of Germany | Christian democracy | Alfred Dregger | 26.4% | |||
| bgcolor= | FDP | Free Democratic Party | Classical liberalism | Heinz Herbert Karry | 10.4% | |||
| bgcolor= | NPD | National Democratic Party of Germany | German nationalism | 7.9% | ||||