I paid for school tuition for my fiance last year can this be written off

Yes, if she qualified as your dependent. Otherwise, no.

However she may use the money you paid to claim the tuition credit or deduction on her own return*. If she is the dependent of her parents, they may claim the money you paid. 

*A student, under age 24, is only eligible for the refundable portion of the American Opportunity Credit, on his/her own return, if he supports himself by working. He/she cannot be supporting himself on support fro other people, 529 plans or student loans & grants. He/she must have actually paid tuition, not had it paid by scholarships & grants.  It is usually best if the parent claims that credit.