In which countries can you register your marriage with a tourist visa?

Most countries are ok, including European countries, Canada, the United States, etc. All are possible. It’s just that you need to have a witness present when you get married. Usually the witness is a friend of the bride and groom. So if it’s just the bride and groom traveling without friends, they won’t be able to find witnesses.

I myself got married in Canada. I have friends who got married in Europe and some in the United States.

In addition, getting married abroad is not recognized when returning to the country, and you still need to obtain a new certificate to register the marriage.