What type of visa do I need to stay in Thailand for 6 months if I am married to a Thai citizen?

Really legally married with a certificate?

A year ago I stayed for 6 months. Due to the Washington DC Thai Embassy not coming through with the visa I paid for (lesson learned don’t use DC embassy) I received a visa on arrival, which at the time was good for 45 days. Within a couple weeks of entry I got a 30 day extension from the local immigration office. As I got close to the end of my 75 days I flew into Vientiane and got a 60 day tourist visa from the Thai embassy there. Then I got another 30 days from immigration. When I got close to the end of that I flew into Saigon and on returning to Thailand I got a 30 day visa on arrival which covered me through to my departure. For the trip to Laos I had to get a Lao visa prior to entry, I got it from their embassy in Bangkok. For Vietnam I got an e-visa ahead of time. I learned a few things along the way and feel more comfortable with long stays there now.

With a Non-O VISA for family/marriage, you can apply for a 1 year VISA which gets you multiple entries at 90 days each entry. Just fly out to a neighboring country for a few days or more, then return to Thailand and you get another 90 days again. That should fulfill your 6 months stay in Thailand. Done it many times. Instructions are on the Thailand website.

You could do that on tourist visas or on a marriage visa.

Multiple entry non-o based on marriage. 1 border bounces. I'm in same situation. 6 months Thailand, 6 months UK.

If its 6 months (anything upto 9 months( then the easiest is the multiple entry tourist visa

What's your nationality and age? Do you mean 1 visit to Thailand for 6 months or many short trips totalling 6 months? How do you fund yourself when you're in Thailand?

Similar situation, I stay 5 months, 1 SE tourist visa + extension, border bounce (though usually do 4-5 day trip), visa exemption + ext. If I wanted to stay 6 months I'd a get a tourist visa from the neighbouring bounce country. Don't see any point in retirement visa for just 5-6 months.

Following.

Were you married in Thailand or in your home country because your marriage has to be recognised in Thailand to get a Non-O marriage Visa (90 day entry). Check with your local Thai Embassy what is required if you don't have a Thai (pink) marriage certificate.

Non-O 3 months + 2 months visit family, run out and get 30 days on arrival and 2 months visit family again.

Class O visa

Marriage visa or Retirement visa if over 50 years old