I've been with my Thai gf for over 3 years now and plan on tieing the knot.

 

When I do, I will want to apply for a marriage visa.

 

Does anyone know whether or not I will need to wait a certain period of time before I do this?

You want to apply for a non immigrant O visa (multi or single entry?) from a Thai Consulate in another country?  Or are you asking converting to a non immigrant O visa entry at immigration and extending on a yearly basis?  There is no wait time if you meet the requirements (financials for conversion and extension and for visas as some locations).  

You can go and get your non-O as soon as you have registered your marriage at the amphur office and have the marriage certificate. You will then extend that by getting the extension of stay based on marriage which is one year at a time.

42 minutes ago, lopburi3 said:

You want to apply for a non immigrant O visa (multi or single entry?) from a Thai Consulate in another country?  Or are you asking converting to a non immigrant O visa entry at immigration and extending on a yearly basis?  There is no wait time if you meet the requirements (financials for conversion and extension and for visas as some locations).  

Want to convert a tourist visa to a marriage visa.

30 minutes ago, SteveK said:

You can go and get your non-O as soon as you have registered your marriage at the amphur office and have the marriage certificate. You will then extend that by getting the extension of stay based on marriage which is one year at a time.

Thanks, this was the answer I was looking for.

5 minutes ago, nailbrains8 said:

Want to convert a tourist visa to a marriage visa.

For that you must meet the financial requirement of 40k per month income or 400k in bank and pay 2,000 baht at immigration office willing to do the conversion process and if using 400k after funds in your account 2 months you can then use TM.7/pay 1,900 baht to request extension of stay for one year at a time.  Money must be in your account but wife will need to be with you for application.  Check with your local immigration office for exact paperwork requirements.

Edited October 9, 20196 yr by lopburi3

The marriage must be consummated 1st with photographic proof for the 1st conversion. After that just sitting together on the bed is fine.