| Election Name: | 1966 Maryland gubernatorial election |
| Country: | Maryland |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1962 Maryland gubernatorial election |
| Previous Year: | 1962 |
| Next Election: | 1969 Maryland gubernatorial special election |
| Next Year: | 1969 (special) |
| Election Date: | November 8, 1966 |
| Image1: | File:Spiro Agnew (MD).png |
| Nominee1: | Spiro Agnew |
| Party1: | Republican Party (United States) |
| Popular Vote1: | 455,318 |
| Percentage1: | 49.50% |
| Nominee2: | George P. Mahoney |
| Party2: | Democratic Party (United States) |
| Popular Vote2: | 373,543 |
| Percentage2: | 40.61% |
| Image3: | 3x4.svg |
| Nominee3: | Hyman A. Pressman |
| Party3: | Independent politician |
| Popular Vote3: | 90,899 |
| Percentage3: | 9.88% |
| Map Size: | 280px |
| Governor | |
| Before Election: | J. Millard Tawes |
| Before Party: | Democratic Party (United States) |
| After Election: | Spiro Agnew |
| After Party: | Republican Party (United States) |
The 1966 Maryland gubernatorial election was held on November 8, 1966. Incumbent Democratic Governor J. Millard Tawes was unable to seek a third term in office. In the election to succeed him, George P. Mahoney, a controversial segregationist, emerged from the Democratic primary due to splintered support for the two major candidates. Baltimore County Executive Spiro Agnew, was nominated by the Republican Party as their gubernatorial candidate. Mahoney and Agnew squared off, along with independent candidate Hyman A. Pressman. Ultimately, Agnew was victorious over Mahoney, with Pressman a distant third. This year was the last time that the state of Maryland elected a Republican governor until 2002. Agnew was later nominated for Vice President by the Republican National Convention, per Richard Nixon's request, in 1968, an election he and Nixon won.
this marks the last time the following Independent city and Counties have voted Republican in a gubernatorial election: Baltimore City, Montgomery, and Prince George’s.
Baltimore paving contractor and perennial candidate George P. Mahoney won the Democratic primary on a segregationist platform, which was possible due to the presence of several strong candidates. Mahoney's slogan, "Your home is your castle--protect it",[1] as well as his stance on many civil rights issues,[2] prompted Baltimore City Comptroller Hyman A. Pressman to enter the race as an independent candidate. Mahoney's controversial stances caused many in the Maryland Democratic Party to split their support between Agnew, which was possible due to his socially progressive views, and Pressman, which enabled Agnew to win the election with a plurality, taking 70% of the black vote.[3]