Johnston residents headed to the polls on November 2, 2021, and the results are in. Incumbent Paula Dierenfeld will be sworn in for two years and incumbents Rhonda Martin and James Evans will be sworn in for four years.
City of Johnston Mayor
| Candidate | Total Votes | % Votes |
| Paula Dierenfeld* | 4,249 | 95.61% |
| Write-in | 195 | 4.39% |
*Incumbent
City of Johnston Council
| Candidate | Total Votes | % Votes |
| Rhonda Martin* | 2,851 | 36.83% |
| James Evans* | 2,685 | 34.68% |
| Adam Haar | 2,112 | 27.28% |
| Write-in | 94 | 1.21% |
* Incumbent
Johnston Community School District
| Candidate | Total Votes | % Votes |
| Clint G. Evans | 3,772 | 16.34% |
Deb Davis
| 3,770
| 16.34%
|
Derek Tidball
| 3,693
| 16.00%
|
Justin Allen *
| 3,228
| 13.99%
|
Jeanie Kerber *
| 3,106
| 13.46%
|
Lya S. Williams
| 2,994
| 12.97%
|
Tiara L. Mays
| 2,492
| 10.80%
|
Write-in
| 24
| 0.10%
|
*Incumbent
For a full list of the Polk County election results, click here.