2021

All real-world events relating to the universe that occurred in 2021.

January

 * January 5 – Haim Shtrum died.
 * January 17 – aired for the first time.
 * January 27 – Cloris Leachman died.

February

 * February 14 – aired for the first time and was broadcast in Canada on Citytv, prior to any other country.
 * February 17 – Rush Limbaugh died.
 * February 21 – "Boy's Best Friend" aired for the first time in the United States on Fox.
 * February 28 – aired for the first time.

March

 * March 2 – Lucas Van Wormer died.
 * March 7 – aired for the first time.
 * March 14 – aired for the first time.
 * March 28 – aired for the first time.

April

 * April 11 – aired for the first time.
 * April 14 – Bernie Madoff died.
 * April 18 – aired for the first time.

May

 * May 2 – aired for the first time.
 * May 9 – aired for the first time.
 * May 16 – aired for the first time.
 * The nineteenth season of ended.

August

 * August 17 – Ernie Ehrhardt died.
 * August 29 – Ed Asner died.

September

 * September 14 – Norm Macdonald died.
 * September 18 – Adult Swim broadcast its final episode.
 * September 26 – aired for the first time.
 * The twentieth season of started.

October

 * October 3 – aired for the first time.
 * October 10 – aired for the first time.
 * October 17 – aired for the first time.
 * October 24 – aired for the first time.

November

 * November 7 – aired for the first time.
 * November 14 – aired for the first time.
 * November 19 – Will Ryan died.
 * November 21 – aired for the first time.
 * November 28 – aired for the first time.

December

 * December 19 – aired for the first time.
 * December 22 – Kirk Benson died.
 * December 31 – Betty White died.