Do Canadian citizens receive a 3 months visa when entering Thailand?

No. 60 days only for Canadians also

@Sam *****

when a Canadian citizen mentions he gets a 90 days visa, he surely means that he can enter with a single entry tourist visa, receive a 60 days stay permit which he can extend for 30 more days stay permit. In his eyes, it would be a "90 days visa". In reality, there is nothing such as a 90-days Tourist visa. There only is a 90-days single entry Non-Imm-O visa based different reasons

USA & Canada (visa exempt) is just a proposal at the moment, don't count on it

The only people getting a promotional 90 days right now is Russia, and that's still based on bilateral agreement. The Chinese are only getting 30 day visa exempt, not 90 days, same as USA and Canada.

If someone with a Canadian passport arrives without a visa they will be stamped in for 30 days visa exempt. They can apply one time for a 30-day extension giving them 60 days total.

Or they can apply for a tourist visa before traveling (Avoid Ottawa if possible and use the Vancouver embassy) and receive 60 days on arrival with a tourist visa and can apply one time for a 30-day extension giving 90 days total.