Maybe check out Christopher Moore

I don’t know you, but I love you already 💖

Neil Gaiman - More on the Fantasy side than irony. His works are still a pleasure. And ofk his collaboration with Terry “Good Omen”. Also check “American Gods” and “Anansi Boys”.

Kurt Vonnegut - Not what you would call “Fun and laugh” works, but his stories are crazy, well written and full of irony and smart social critics.

I’d definitely agree with the people recommending Robert Rankin.

Tom Sharpe is also funny (Wilt, Porterhouse Blue, etc.)

Also (disclaimer that it’s by someone I used to know which may affect my judgement) Go Up by Simon Broadbent is clearly influenced by the Terry Pratchett books set in Ankh Morpork.

I didn’t like it quite as much, and it is more middle grade, but A Wizard’s Guide to Defensive Baking feels kind of Pratchett influenced.

I recently read The Stranger Times by Caimh McDonnell, an urban fantasy about a tabloid reporting on supernatural events that’s very tongue in cheek and although the humour doesn’t always hit, it did remind me of Rivers of London by ways of Terry Pratchett. The characters are certainly very Pratchett-ian. The story starts of with the Stranger Times looking for a “new Tina” a.k.a. assistent editor because the editor is insufferably rude and terrible to people. The job description reads: “Publication seeks desperate human being with capability to form sentences, using the English language. No imbeciles, optimists or Simons need apply.”

There’s always Neil Gaiman. His style is definitely different, but you can feel some similarities. He and Pratchett wrote Good Omens together. Check out Stardust, the Graveyard Book, or American Gods. And of course The Sandman, but it is darker.

Definitely read some Wodehouse.

Edit: Stanisław Lem’s Pirx series as well!

One that reminded me a lot of Discworld was the Magic 2.0 series by Scott Meyer. First book was called Off to be the Wizard.

Tom Holt is much in a similar vein as Pratchett (even shared the same cover artist for a while) with his satirical takes on fantasy & fairy tale tropes.

Surprised no one has mentioned Robert Rankin, who has a darker view that Adams but is good at satirical takes, even though some of his works do feel dated since they were written for the contemporary audience of the publications time.

Diana Wynne Jones is also recommended, she was an influence on Pratchett to a degree. She picks apart a lot of fantasy tropes in her books. she was also a friend and teacher to Gaiman. Most people know her for the Ghibli adaptation of her book Howl’s Moving Castle.

Jasper Forrde has been described to me as like Adams but haven’t read his book yet.

and finally the Gormenghast series by Mervyn Peake, which was referenced a lot in the early Discworld novels.

I’m not sure if it will scratch that itch, but Pratchett’s daughter Rhiannon is co-releasing something Discworld related in the near future.

I’m mostly in the same boat, except I haven’t been able to pick up the Shepherd’s Crown. I’m still not ready for it to be over.

It’s actually a very dark book in some points, but Joseph Heller’s Catch-22 is that style of absurdist humor set during World War II. My English teacher assigned that one to me when he found out I loved Hitchhiker’s Guide.

I second (third? fourth?) the Kurt Vonnegut suggestions too. I have never regretted reading anything with his name on it.

I think a lot of the comments are focusing on similar subject veins, but for similar writing styles as you asked, I would suggest checking out Christopher Moore or jason pargin( former pen name David Wong)

Try the stories of Harry Harrison.

Maybe Ernie Cline, Ready Player One and Armada or Andy Weir, The Martian, Artemis, Project Hail Mary