Can I transfer my retirement visa to a passport of a different nationality?

Why?

You would need to exit and return with your 2nd passport and start over ,bank account 800k ect and your two passports will be linked together

@Yafit *******

the only authority that can give you a 100% correct reply, is the Immigration which serves the area where your current accomodation is

@Yafit *******

the 90-days Non-Imm-O Retirement Visa (I am not sure if you mean the visa or if you are already on the 1-year extended stay permit) got issued nationality specific. I would say it is impossible to get it transferred to another passport with a different nationality. . . . . . . . And as a rule, Immigration cannot transfer any visa, because visas are issued by embassies, and embassies are regulated by the Ministry of Foreign Affairs, while Immigration is under the Ministry of Interior. Immigration can only transfer their own stamps

You cannot move a visa/extension from one nation's passport to another. You can only move your extension from an old passport to a replacement passport of the same nationality.

The only way to do what you want is to effectively end your current permission to stay and start over completely with a new one using the other passport. You would need to leave Thailand and then return using your other passport (can only be done by air as you cannot change passports at a land border). Then start the retirement visa process all over from the 90-day non-O visa conversion to the 1-year extension.