Can my wife apply for a Trailing Spouse visa on my Non-O Retirement Visa in Thailand, or does she need her own?

Could yo do your retirement visa 3 month apart and switch the 800k from your bank to hers each time you renew?

I would wager that neither of you are on ANY visa at this time 😮 and if you looked at the stamp in your passport you'd see that it says "extension of stay permitted until" and has a date on it

What I'm getting at is that you won't be switching to any Non-O anything visa, all you'll be doing is changing the reason for your extension from the one you have now based on education to a yearly extension based on being over 50 (retirement).

There shouldn't be much problem for you to switch reasons, you would get the documents from your school saying you stop studying on xxx date, get all the documents, bank letter, copies etc, go to the immigration office that issued the ED extension, cancel it and immediately apply for a new yearly extension based on retirement.

NOW as far as if your spouse can do the same thing but change the reason for her ED extension to one based on trailing spouse of a retiree, that's gonna be between you and the immigration office you deal with for the extensions.

I'd say go over well before your current extensions expire, tell them you plan on "changing the reason for your extension" do not say you want a Non-O nothing, because they'll tell you that you have to leave to do that <- which is true.. You don't want ANY new visa, you just want to change the reason for why you have an extension.

Will it work for her, honestly don't know at all, but it should work for you without any hiccups. You're going to have to talk to your immigration office about the "reason changes" for the extensions and see what they say