If a Thai woman gets denied entry for whatever reason in lets say Korea shortly before she applies for a spouse visa to the EU, will this affect her application for the spouse visa?

More information needed as it depends on why she was denied entry.

 

Which country and why?

 

Which EU country is she applying to?

 

Is her spouse a national of that country, another EU country or neither?

Korea, denied because of suspicion (without any hard evidence) of working without a visa.

 

EU country: Netherlands.

 

I'm from The Netherlands, the country for which she will apply for spouse visa.

They will probably also think she is a hooker... 

It would certainly be taken into consideration, and of course she should declare it.

 

She should submit the full details of the refusal with the application, I suspect it wouldn't be an automatic refusal, the Dutch are pretty fair and would consider all the facts surrounding her application.

Is there anything stamped in the passport? If no. No issue. If yes. Get a new passport. 

What is a "Spouse visa"?  It will either be a tourist visa to visit you, or an MVV visa, or which she will first have to do the "inburgering buitenland" at the embassy in Bangkok. The latter is to come and reside in the Netherlands. With a MVV visa she will be allowed to work, so there would be no reason to deny this just because she was denied a Korean visa.

 

A tourist visa, on the other hand, would most probably be denied on those same grounds.

 

2 minutes ago, Snow Leopard said:

Is there anything stamped in the passport? If no. No issue. If yes. Get a new passport. 

The refusal must be declared, failure to do so would probably result in the application being automatically refused if detected.

What you seem to be suggesting is very risky for the applicant.

7 minutes ago, theoldgit said:

The refusal must be declared, failure to do so would probably result in the application being automatically refused if detected.

What you seem to be suggesting is very risky for the applicant.

I haven't seen this particular application form but the ones I have done in the past have mainly said "Have you been denied entry into the country that you are actually applying to for the visa to enter"  Not any other country. Anyway, this would be a choice the OP needs to make.