| Election Name: | 1978 Maine gubernatorial election |
| Country: | Maine |
| Type: | presidential |
| Ongoing: | no |
| Previous Election: | 1974 Maine gubernatorial election |
| Previous Year: | 1974 |
| Next Election: | 1982 Maine gubernatorial election |
| Next Year: | 1982 |
| Election Date: | November 7, 1978 |
| Nominee1: | Joseph Brennan |
| Party1: | Democratic Party (United States) |
| Popular Vote1: | 176,493 |
| Percentage1: | 47.8% |
| Nominee2: | Linwood E. Palmer Jr. |
| Party2: | Republican Party (United States) |
| Popular Vote2: | 126,862 |
| Percentage2: | 34.4% |
| Nominee3: | Herman C. Frankland |
| Party3: | Independent (United States) |
| Popular Vote3: | 65,889 |
| Percentage3: | 17.8% |
| Map Size: | 300px |
| Governor | |
| Before Election: | James B. Longley |
| Before Party: | Independent (United States) |
| After Election: | Joseph Brennan |
| After Party: | Democratic Party (United States) |
The 1978 Maine gubernatorial election took place on November 7, 1978. Incumbent Independent Governor James B. Longley had promised to not seek a second term when he was elected in 1974, and held true to his pledge. Former State Senator Joseph E. Brennan of the Democratic Party defeated both challenger Republican Linwood E. Palmer Jr. and right-wing independent candidate Herman Frankland. Richard Carey unsuccessfully ran for the Democratic nomination, while Charles Cragin unsuccessfully ran for the Republican nomination.