Can we marry after moving to Europe, for my fiance to stay?

[ComatosePen]

I'm a UK citizen and I'm planning on going to live in Europe soon. Possibly either Portugal or Spain. I want my fiance (who is from the USA) to live with me there. I know that in order for her to have legal residence there with me, she needs to be registered as my spouse.

My question is, do I need to be married first in order to legally have my fiance live with me in Europe, or can I marry her once she gets here? And if I can marry her once she gets to Europe, could she come on a tourist visa? That would be our preferred, plan if it is possible.

Once she is in Europe, how easy or possible would it be to get married there? What would it involve? (the wedding itself is not an issue since we are not really into ceremonies, but just the legal stuff and paperwork). I'm worried about her getting to Europe and then having it be too hard or impossible for her to marry or stay there with me.

Is it a better idea to try to marry her outside of the EU first?
(Also, we are both female, which I'm not sure makes it difficult for us to carry out our plan.)

[ALKB]

I'm a UK citizen and I'm planning on going to live in Europe soon. Possibly either Portugal or Spain. I want my fiance (who is from the USA) to live with me there. I know that in order for her to have legal residence there with me, she needs to be registered as my spouse.

My question is, do I need to be married first in order to legally have my fiance live with me in Europe, or can I marry her once she gets here? And if I can marry her once she gets to Europe, could she come on a tourist visa? That would be our preferred, plan if it is possible.

Once she is in Europe, how easy or possible would it be to get married there? What would it involve? (the wedding itself is not an issue since we are not really into ceremonies, but just the legal stuff and paperwork). I'm worried about her getting to Europe and then having it be too hard or impossible for her to marry or stay there with me.

Is it a better idea to try to marry her outside of the EU first?
(Also, we are both female, which I'm not sure makes it difficult for us to carry out our plan.)

Whether you can marry on a visitor visa (or visa waiver in her case) depends on the legislation of the country you want to get married in.

For example, in the UK it's not allowed (but some people succeed), in Germany it's a kind of grey area but very complicated, in Denmark it's relatively easy and possible, etc.

[Casa]

is actually permitted to marry in the UK while on a visitor visa although Immigration Rules would say it shouldn't be your intention when you enter as a visitor.
From experience, (although as a resident not a visitor) Spain is particularly slow in processing paperwork for a marriage between non-nationals.