Deaths
- January 20 — Jô Shishido
- March 17 — Lyle Waggoner
- March 19 — Nazzareno Zamperla
- April 3 — Brian Degas
- April 4 — Jay Benedict
- April 16 — Andrew J. Fenady
- April 17 — Sergio Fantoni
- April 26 — Aarón Hernán
- May 9 — Little Richard
- May 12 — Michel Piccoli
- May 26 — Cindy Butler
- June 8 — Fabrizio Mioni
- July 6 — Ennio Morricone
- July 24 — Regis Philbin
- July 25 — John Saxon
- August 13 — Giancarlo Ferrando
- August 23 — Lori Nelson
- August 31 — Bent Vejlby
- September 28 — Gene Corman
- October 19 — Smith Wordes
- November 23 — Abby Dalton
- December 16 — Emil Cadkin
- December 31 — John "Bud" Cardos
Special Premieres
- May 3 — The MST3K LIVE Social Distancing Riff-Along Special
- October 30 — Mystery Science Theater 3000 - The MIGIZI Fundraiser Shorts
- November 26 — Turkey Day '20
Home Media Releases
- August — MST3K vs. Gamera: Volume XXI returns to print.
Events
- February 22 — Destroy All Movies.
- March 4 — The Great Cheesy Movie Circus Tour concludes in Reading, PA.
- April 3 — Frank Conniff announces the discontinuation of the podcast Movie Sign with the Mads on Twitter.
- July 21 — The Mads livestream riff of Glen or Glenda.
- August 18 — The Mads livestream riff of The Tingler.
- September 1 — Shout! Factory TV and the MST3K Twitch channel run a marathon of the five Comedy Central Gamera episodes.
- September 15 — The Mads livestream riff of Walk the Dark Street.
- October 20 — The Mads livestream riff of A Night of Shorts.
- October 30 — The Second Annual Puppet Camp and Startling Conclusion of the MIGIZI Fundraiser!
- November 17 — The Mads livestream riff of The Brain from Planet Arous.
- December 15 — The Mads livestream riff of Santa Claus vs. the Devil.
Community content is available under CC-BY-SA unless otherwise noted.