2020 San Diego County Board of Supervisors election

The 2020 San Diego County Board of Supervisors election was held on Tuesday, November 3, 2020, with the primary election held on March 3, 2020. While the San Diego County Board of Supervisors is officially a nonpartisan institution, Republicans controlled four out of the five supervisory seats, while a Democrat held one. However, the election resulted in a Democratic majority for the first time in decades after Nora Vargas and Terra Lawson-Remer respectively won supervisorial elections in the first and third districts.

Even though county supervisor elections are officially nonpartisan in California, Republicans held a 4–1 majority in the San Diego County Board of Supervisors heading into the 2020 election, with the one being a lone Democrat.

In the general election, Democrats Nora Vargas and Terra Lawson-Remer respectively won supervisory seats in the first and third districts, assuring a Democratic majority in the next term and for the first time in a generation.

First district runoff results by precinct .mw-parser-output .legend{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .legend-color{display:inline-block;min-width:1.25em;height:1.25em;line-height:1.25;margin:1px 0;text-align:center;border:1px solid black;background-color:transparent;color:black}.mw-parser-output .legend-text{}  Vargas   50-55%   55-60%   60-65%   65-70%   70-75%   >75%   Hueso   50-55%   55-60%   60-65%   65-70%   70-75%   >75%   Tie   No data

Second district runoff results by precinct   Anderson   50-55%   55-60%   60-65%   65-70%   70-75%   >75%   Vaus   50-55%   55-60%   60-65%   65-70%   70-75%   >75%   Tie   No data

Third district runoff results by precinct   Lawson-Remer   50-55%   55-60%   60-65%   65-70%   70-75%   >75%   Gaspar   50-55%   55-60%   60-65%   65-70%   70-75%   >75%   Tie   No data

On January 5, 2021, the Board of Supervisors elected Nathan Fletcher as the new chair, succeeding Greg Cox.