Can I get a re-entry visa at Bangkok airport without my marriage certificate?

"...

Go to International Departure Gate 2 when going to the Security Check at Suvarnabhumi Airport

Go to the Right at the Bottom of the Escalator after the Security Check

It's the easiest way to find the Re–Entry Permit Counter (they put the name "Re–Entry Visa")

You can bring a filled TM.8 Form to save 5 minutes to fill the form there

You can bring a passport-size Photo to save an extra 200 baht Service Fee

...."

if the Admins/Moderators of another Thai Visa Advice Q&A Facebook Group would permit me to share info about getting a Re–Entry Permit at Suvarnabhumi Airport as Bangkok has 2 airports and the OP didn't specify which airport....

Go to immigration they will make a reentry I think 1000 bth

I got mine done at the local immigration office, a few days before departure. Felt safer..

I find always good practise to take photos of relevant certs just in case of loss or if required. But dont need it for re entry permit

Yes and no.

You can get a re-entry permit at the airport. Nothing to do with your marriage certificate.