There are approximately 250 golf courses in Thailand - there are very few public golf courses and most of them are privately owned and many of them are owned and operated by the Armed Forces and various utility companies.  Apart from a few very exclusive private members clubs, you can get access to most golf courses in Thailand. Only around 150 courses are up to international standards and suitable for visiting tourists.  The main golfing destinations in Thailand are Bangkok, where there are round 50 courses, Pattaya which is a 2-hour drive from Bangkok which has around 30 courses.  Hua Hin is also accessible from Bangkok and is home to 12 golf courses.  You can also play golf in Chiang Mai (12 courses),  Phuket and the nearby province of Phang Nga which have 10 courses.
Although more remote, you will also find golf courses in Kanchanaburi which is alongside the River Kwai and also dotted among the Khao Yai National Park, about three hours north of Bangkok.