Do you need a return flight for a tourist visa to Thailand?

I just bought a one-way ticket. USA Embassy asked me for my return flight an hour later... Add usa to your list!

I will be forgetting Thailand until this virus is in control

Every embassy has the option to give you a visa or not. Every immigration officer has the option to allow you in - or not. In both cases the things they may or may not ask for will differ by who is asking.

From what I remember Manila is quite strict about their requirements. I can show up with some of their requirements and a copy of this post and request a visa, I am sure they will decline my request.

Australia has a few (5 I think) Thai embassies. Each with different requirements. What one embassy will find acceptable and grant me a visa, another embassy may not.

You could skip the visa stuff entirely. You could show up at the airport and not be asked for anything because the airline is in a hurry. Then continue on to immigration and the immigration officer may not ask for anything and grant you entry. That doesn't mean that will happen for always for everybody.

Couple of points to consider.

A) This is a foreign country (to anybody seeking tourist visa), it is best to act like you are a guest.

B) Everybody can have different experiences depending on several factors (Immigration officer mood, the asshole in front of you, the Embassies policy makers motivations, embassy employee's mood, etc etc). Because you have one experience does not mean you are guaranteed the same experience the next time.

C) The rules and guidelines - help assure you are not the asshole mentioned in 'B'.

Also noteworthy, I have always had success with bus tickets for onward travel requirements. may not be applicable currently - but 'onward travel' doesn't mean 'transportation home'

I have never ever been asked for a return ticket by the airline nor immigration while entering Thailand since first entering in 2010. I must be very lucky according to some.

Every embassy is putting out different info

It might not be required to get the visa, but most airlines will refuse travel if you cannot show that you're leaving before the visa expires.

I was asked by consulate for return ticket .