Thanks for the plug
Not enough love in here for Rev Left Radio. My boy Breht has been out here making high quality educational communist podcasts for years!
Also check out his other shows, Guerilla History, and Red Menace
For climate and scifi enjoyers: the interview with Kim Stanley Robinson about "ministry for the future" is a really great episode.
I always take revleft as a given on these lists, but you're right another plug never goes astray
Always gotta suggest Chapo because I used the subreddit for a year without knowing about the podcast.
My #1 rec is trueanon if you don’t listen already
Ghost stories for the end of the world is great for psychedelic deep state conspiracy shit
I really like last born in the wilderness, he covers a lot of topics but most regularly climate change and the Anthropocene. It’s heavy, but insightful
The Matt and Chris spin-off shows are great, hell of presidents and hell on earth
is this site's official podcast and yet nobody has mentioned it, disgraceful!Death Panel is so good but I’ve mostly had to stop listening to it because it’s too upsetting
I listened to the year in review and made myself mad for like a week.
Boonta Vista is great if you have a stupid sense of humor like mine.
Tech Won't Save Us / This Machine Kills if you have a luddite bent, both are amazing but somewhat academic.
If you can stand the incredibly obnoxious I Heart Radio ads, Alphabet Boys is a very well produced series about a fed infiltrating the BLM movement in 2020. The second season is about a fed clusterfuck involving CIA and FBI butting heads during a sting operation.
I've also been listening to If Books Could Kill, which is all about skewering shitty self help books.
Infrequent but usually good:
Subscribe but don't autodownload: Knowledge Fight, r/askHistorians podcast, Hamilton Morris Podcast, I don't speak german, Studs Terkle Archive
Recently added: Bringham Young Money, Seeking Derrangements, Where there's woke
RIP: Bottlemen, posting through it, spycops, Eat the Rich
Limited series: This Land, The Log Books
Of those mentioned already by others the ones I will especially endorse are Qanon anonymous, tech won't save us and trash future. Some of the other ones I will have to listen to.
Age of Napoleon
approved and on two guest episodes
Some less political ones:
Oh No Ross and Carrie is a podcast where they investigate paranormal claims and rate them on how pseudoscientific, dangerous, and creepy they are. I almost always enjoy it but it's worth jumping around and listening to what intrigues you.
Just the Zoo of Us: they talk about two animals per episode and rate them at the end.
The Empty Bowl: a meditative podcast about cereal news and reviews.
Hey Riddle Riddle: Chaotic podcast where they do a lot of improv scenes and bits, and also they try to solve riddles.
The Dollop is pretty enjoyable. Waiting to see whether Dave or Gareth says something that gets them arrested first as they get more and more unhinged by reality.
Oh also Blowback, of course.
That new John Brown one isn't half bad.
Dave is such a total dick and totally unable to accept any criticism of any kind, mild pushback or even the plebs talking in his general direction. It will absolutely be him. Also his researchers should unionize to stop him taking the fucking credit
It's gonna be Dave because it's very funny to egg him on and make him very mad online
It is, but Gareth is starting to lose it. Things are getting to him. He's been doing a lot shrooms too, to cope, I think.
The soul cycle episode I just kept going “Damn, Gareth isn’t doing well”
Worst of All Possible Worlds - Case studies in the pop culture of a dying empire
The Dollop - Comedy American history. The episode 1908 New York to Paris Car Race is one of the funniest things I’ve ever heard
Trashfuture - British Chapo. Also making fun of startups.
Well There’s Your Problem - Leftist comedy podcast about engineering disasters.
A More Civilized Age - Leftist analysis of Star Wars Clone Wars, Rebels, and more recently Knights of the Old Republic
Trillbilly Workers Party - Southern leftists
Short series:
Alphabet Boys - A cop infiltrated the BLM movement in 2020
Operation Midnight Climax - CIA/FBI drug related fuckery
Santiago Boys - Rise and fall of Allende
Actually Existing Socialism (also available on podcast apps, obviously)
Imo extremely underrated. It focuses on interviewing experts in their field - historians, anthropologists, journalists, etc. - on their area of specialisation.
It's a really good podcast if you like deeper dives and you're either looking to get hyped about books or you want to get the thesis of a book without doing the reading (I see you!)
The episodes interviewing Bruni De La Motte and Victor Grossman on the GDR are particularly good but basically all of the episodes are great.
Chapos pretty bad without Matt ATM. I guess the older eps check out but ymmv.
Trillbillies, Citations Needed
I like Remember Shuffle. they analyze pop culture from the aughts.
Generation Loss is a podcast about movies hosted by leftists (will get into leftist politics if the movie calls for it, like their recent talk about Robocop).
Guys is a podcast about "Guys" (aka an episode about Lawn Guys or Bourbon Guys or Audiophile Guys). The hosts are leftist, but the podcast is mostly focused on comedy and not politics.
Beep Beep Lettuce is a leftist podcast about the news and smoking weed.
Work Stoppage is a podcast about labor and unionization.
Blowback is a podcast about American interventions abroad and the consequences of those interventions.
Death Panel is a leftist podcast about covid and public health.
Trillbilly Worker's Party is a leftest podcast about how they're sending us all to the rubber room.
Trashfuture - british leftist tech pessimist podcast, talks about political and tech news, they are very funny though some bits may be inscrutable to new listeners
Corner Späti - english language german leftist podcast that talks primarly about european news
People's History of Ideas Podcast! 
bigsofttitty.png is just a funny podcast made by two Australians who love each other and it's cute
I will just add stuff to the list that hasn’t already been commented.
-secret antenna (pretty obscure leftist/conspiracy theorist kind of podcast hosted by women)
-acid horizon (heavy theory/philosophy)
-why theory (also heavy theory)
PS thanks to everyone else for the recommendations!
Chapo for US stuff, Trashfuture for UK stuff and Citation Needed for media-litteracy.
Quorators
I usually hate the “reading posts and riffing” type stuff, but idk I think the guys are funny. Some of the guests also get offended by the questions about bestiality which is kinda funny. They recently got fired from a partnership with Cracked because they supported Palestine and clogged a toilet at its office lol
I second Quorators. It's a comedy podcast hosted by two leftists so you can enjoy the jokes knowing they're not going to hit you with a massive bit on transphobia.
I like having a podcast by people with politics I agree with that isn't about politics exclusively.
This Machine Kills
Work Stoppage
The Red Nation Podcast
The Dig (Jacobin shit, but a number of good Palestine episodes lately)
Working People
Corner Spati
Antifada
Radio War Nerd
Whenever Sean KB from Antifada gets into a discussion with Derick Varn my brain explodes
Varnvlog - he interviews basically everyone and really just has unparalleled output
The Regrettable Century - religion and medieval history podcast but communist
Fight Like an Animal - biology/psychology focused theory podcast (leans more anarchist than marxist)
People's History of Ideas - very good/long and as of now incomplete history of the Chinese Revolution, think Revolutions but better
Bad Gays - fun podcast about complicated to horrible queer people in history (left adjacent)
Varn is a guy I often disagree with, but I still think most all of his takes are pretty solid
Yeah you can't say he doesn't know his stuff. I do get annoyed with some of the purposefully anticharismatic things he does cus it makes it hard to show his stuff to people who aren't terminally online communists but I think he's still interesting even when I do disagree with him.
Biology focused theory podcast sounded cool and then I saw the episode title “The Incompetent Authoritarianism of Vladimir Lenin” 
Kill James Bond makes me smile every time
Regrettable century (more pessimistic marxist podcast)
Know your enemy (soft socdems talking mainly about conservatives thinkers, but very nice people)
General intellect unit 🧠 (random cybersyn topics)
From alpha to omega 🧠 (even more random leftist topics)
Swampside chats 🧠 (more focused leftcom-ish theory)
Gladio free europe (random history topics)
others already mentioned here
Ghost Stories For The End Of The World
TrueAnon
Guerrilla history, red menace, rev left radio
Quorators has been my sleep aid for the last few months.
Work Stoppage for labor news
Kill James Bond for entertainment
Podcast recommendations, episode discussions, and struggle sessions about which shows need to be cancelled.
Rest In Power, Michael Brooks.