The 2021 Sporting Kansas City season was the twenty-sixth season of the team's existence in Major League Soccer and the eleventh year played under the Sporting Kansas City moniker. The season began on April 17.
Sporting KC players reported for a seven day quarantine period involving medical exams and testing on March 1. The team then trained for six weeks beginning on March 8 before the season started on April 17. Sporting KC began a one week voluntary training on March 1 before heading to Arizona on March 7. The team then began preseason training and played 4 preseason matches on March 13, March 20, March 24 and April 3 before returning to Kansas City on April 3.
<small>Per Major League Soccer and club policies terms of the deals do not get disclosed.</small>
Draft picks are not automatically signed to the team roster. Only trades involving draft picks and executed after the start of 2020 MLS SuperDraft will be listed in the notes.
<small>Kickoff times are in CDT (UTC-05) unless shown otherwise</small>
Preseason schedule announced on March 1, 2021.
|- ! colspan="14" style="background:#dcdcdc; text-align:center"|Goalkeepers
|- ! colspan="14" style="background:#dcdcdc; text-align:center"|Defenders
|- ! colspan="14" style="background:#dcdcdc; text-align:center"|Midfielders
|- ! colspan="14" style="background:#dcdcdc; text-align:center"|Forwards
|- ! colspan=14 style=background:#dcdcdc; text-align:center| Players who have made an appearance or had a squad number this season but have left the club |-