My fiancé is a legal resident for more than 10 years and we plan to get married. Would it be better for him to apply for his citizenship before or after we get married? Would there be a difference with the process and fees?
Thank you!

I would say that the time that it would take for him to complete the citizen process would remain the same regardless of the time and date of the marriage.

From experience these things take time (and money) Prepare for a bit of a journey.

FYI Technically I would suggest you wait until after the wedding to complete the citizen process. For there is always a chance that he may not pass.

Why make your life harder planiing for citizenship while planning for a wedding at the same time?

Marry the man first and then figure out the status of his citizenship. (unless you'd like to do it the opposite way that would work as well)

Just do one thing at a time.

I assume that you are talking about US visa... if this is correct then your best bet is to wait until he becomes naturalized...

If you file for immigrant visa as spouse of US citizen, it will take you less than a year to obtain visa and go to US.

But if you file for immigrant visa as spouse of a permanent resident, it takes between 5-6 years depending on the country where you live, and you won't be able t obtain any other non-immigrant visa to visit him. Most important thing, if you divorce before approval of your case, you will have hard time with US immigration in the future when you apply for immigrant visa with someone else.

Good luck.