The following is a summary of Donegal county football team's 2021 season.
Paul Fisher departed as strength and conditioning coach and Antoin McFadden replaced him. Karl Lacey also departed from the management team. James Gallagher returned as goalkeeping coach (his second time in that role), replacing Andrew McGovern.
There was no McKenna Cup in 2021 due to the impact of the COVID-19 pandemic on Gaelic games.
The 2021 competition was delayed due to the COVID-19 pandemic.
Donegal qualified for the semi-finals.
The draw for the 2021 Ulster Championship was made on 22 April 2021.
Due to the impact of the COVID-19 pandemic on Gaelic games, there was no back-door route into the All-Ireland Championship. Therefore, because Donegal did not win the Ulster Championship, they did not qualify for the 2021 All-Ireland Championship.
One nomination, for Michael Langan