The 2021 Houston Dynamo FC season was the 16th season of the team's existence since joining Major League Soccer (MLS) prior to the 2006 season. It was the team's second season under head coach Tab Ramos and seventh season under general manager Matt Jordan. On August 30, with the team on a 15-game winless streak, Jordan was fired. On November 1, with one game left in the season, Pat Onstad was hired as the new GM.
The Dynamo finished the season last in the Western Conference for the second consecutive season, failing to qualify for the playoffs for the 7th time in 8 seasons.
On the front office end, it was Gabriel Brener's sixth season as majority owner and John Walker's third season as President of Business Operations. On June 22, Ted Segal became majority owner after purchasing a controlling stake of the Dynamo and Dash for a reported $400 million. Former majority owner Brener kept a minority stake in the team, with James Harden, Oscar De La Hoya, and Ben Guill keeping their minority stakes. Minority owner Jake Silverstein sold his part of the team.
In October, BBVA Stadium was rebranded as PNC Stadium following PNC Financial Services' acquisition of BBVA USA.
Appearances and goals are totals for MLS regular season only.
<small>Per Major League Soccer and club policies terms of the deals do not get disclosed.</small>
On July 20, U.S. Soccer announced that the Open Cup would be cancelled for 2021 and would resume in 2022.