Widest clipless MTB shoes

Maybe Lake, they do specific wide versions.

Back around 1990, Greg Lemond switched from time shoes to Carnac (something to do with his ‘plates of meat’).

https://www.planetx.co.uk/products/carnac-mode-mountain-bike-spd-trail-shoe-black

I have a pair of the older Lake wide shoes, which aren't very nice. The whole shoe is wide in a crude way, including the heel.

But, the newer MX169 and MX201 are a bit of a revelation. Much like Altra trainers they have a normal heel, reasonable volume with a lovely wide toe box. Instant favourites!

I got mine from Salt Dog.

Yeah, I can to say that Lake are probably worth a look.

As are Salt dog. They've got a Size guide on the website that's pretty good.

Leatt clip shoes are really roomy

Laske 201 & 169 are the only proper wide toebox shoes (by a larger established brand). Even the other lake "wide" fit models have rather pointy toe boxes

This thread has some pictures for comparison.

https://singletrackworld.com/forum/topic/wide-mtb-shoea/

Sidi Mega. They do a number of shoes in the mega sizes. I had one pair of Dominators for 15 years, still got them actually, but the sole has worn out, replaced then 2 years ago, they are definitely wider than the Lakes wide shoes.

I've got a pair of Etnies that are nice and roomy .

I think the answer is to find someone selling a 15 year old pair of hardly used ones. They're the only shoes I find comfortable. They look awful though so it's probably worth the pain (and £££) to look fashionable in new ones.

I've got some Pearl Izumi mtb/gravel shoes that are quite wide, I also have wide feet and they fit me well.

The other option is just to size up, which is what I've done with Shimano and Five-ten.