| Election Name: | 1820 Louisiana gubernatorial election |
| Country: | Louisiana |
| Type: | presidential |
| Ongoing: | No |
| Previous Election: | 1816 Louisiana gubernatorial election |
| Previous Year: | 1816 |
| Next Election: | 1824 Louisiana gubernatorial election |
| Next Year: | 1824 |
| Election Date: | July 5, 1820 |
| Flag Image: | Flag of the United States (1820–1822).svgborder |
| Image1: | Governor Thomas B. Robertson.jpg |
| Nominee1: | Thomas B. Robertson |
| Party1: | Democratic-Republican Party |
| Electoral Vote1: | 49 |
| Popular Vote1: | 1,903 |
| Percentage1: | 40.08% |
| Nominee2: | Pierre Derbigny |
| Party2: | Democratic-Republican Party |
| Electoral Vote2: | 0 |
| Popular Vote2: | 1,187 |
| Percentage2: | 25.00% |
| Image4: | No image.svg |
| Nominee4: | Abner L. Duncan |
| Party4: | Democratic-Republican Party |
| Electoral Vote4: | 0 |
| Popular Vote4: | 1,031 |
| Percentage4: | 21.71% |
| Image5: | Jean Noel Destrehan.jpg |
| Nominee5: | Jean Noel Destréhan |
| Party5: | Democratic-Republican Party |
| Electoral Vote5: | 0 |
| Popular Vote5: | 627 |
| Percentage5: | 13.21% |
| Governor | |
| Before Election: | Jacques Villeré |
| Before Party: | Democratic-Republican Party |
| After Election: | Thomas B. Robertson |
| After Party: | Democratic-Republican Party |
The 1820 Louisiana gubernatorial election was the third gubernatorial election to take place after Louisiana achieved statehood. Under Article III Sec 2 of the 1812 Constitution of the State of Louisiana the Governor was elected in two steps. On the first Monday in July, eligible voters went to the polls and voted. The returns were sent to the President of the Louisiana State Senate. On the second day of the session of the Louisiana State Legislature, the Louisiana House of Representatives and Senate met in joint session and voted between the top two candidates. The candidate who received a majority in General Assembly became governor.
Popular Vote[1]
| Candidate | Votes received | Percentage |
|---|---|---|
| Thomas B. Robertson | 1,903 | 40.08% |
| Pierre Derbigny | 1,187 | 25.00% |
| Abner L. Duncan | 1,031 | 21.71% |
| Jean Noel Destréhan | 627 | 13.21% |
| Total Vote | 4,748 | |
General Assembly Vote[1]
| Candidate | Votes received | Percentage |
|---|---|---|
| Thomas B. Robertson | 49 | 96.08% |
| Blank | 2 | 3.92% |
| Total Vote | 51 | |