The Mindless Summer was a series of live-streaming events that took place in August and September of 2021.

On five consecutive Fridays, episode of Mystery Science Theater 3000 were streamed on the show's YouTube channel, hosted by the current/upcoming casts and crew. These events are similar to the Live Riff-Along of 2020 and the events held during the Let's Make More MST3K crowdfunding campaign.

Announced Episodes

Livestream Air date Episode / Event Featuring
I August 6 Experiment #817 - The Horror of Party Beach Matt McGinnis, Tim Ryder, Nate Begle, and Beth 'Beez' McKeever
II August 13 Experiment #414 - Tormented Matt McGinnis, Yvonne Freese, Rebecca Hanson, and Conor McGiffin
III August 20 Experiment #1005 - Blood Waters of Dr. Z Matt McGinnis, Nate Begle, Tim Ryder, Jonah Ray, and Joel Hodgson
IV August 27 Experiment #204 - Catalina Caper Matt McGinnis, Rebecca Hanson, Conor McGiffin, Felicia Day, and Baron Vaughn
V September 3 Experiment #608 - Code Name: Diamond Head Matt McGinnis, Emily Marsh, Tim Ryder, Baron Vaughn, and Hampton Yount