The answer to this question is yes and no. If a you are planning on staying in Thailand for 30 days or less as a tourist and have a return ticket out of Thailand (or proof of leaving within 30 days), then you do not need a visa. If you are planning on staying past 30 days, extensions of an additional 30 days are many times given but must be applied for at the address below. For longer stays, a visa is required. If you are traveling on business, conference, research, study, or for other non-tourist reasons, then a non-immigrant visa is required. If you are only changing planes in Thailand, no matter the purpose, then you do not need a visa.
Immigration Bureau
Soi Suanplu
South Sathorn Road
Bangkok, 10120, Thailand
0-2287-3101-10
http://www.immigration.go.th
If your travel to Thailand requires a visa, then apply for one ahead of time. The process is rather simple and can be submitted by mail. You will need the following: a passport with at least six months of validity, a completed application form (see link below), a recent passport photo, and cash or money order (recommended) with the proper amount per visa. The visa application fees for tourist visas have been waived until March 4, 2010. It is important to include a self-addressed stamped envelope for the return of the passport.
If you wish to mail your visa application, then put all the application materials in an envelope (a tracking number is recommended due to nature of the package) and mail to the following address:
Application For Visa
Royal Thai Embassy
180 Island Park Drive
Ottawa, Ontario K1Y 0A2
(613) 722-4444
http://www.thaiott@magma.ca
If you have reservations against sending the application materials through the mail, you can apply in person. Visa issuing offices are located at the Embassy in Ottawa and the Consulates in Montreal, Toronto, Vancouver, Edmonton, and Calgary. For full addresses and phone numbers, visit www.magma.ca/~thaiott/visa3.htm.