Hello. I´m already working here in Canada and I have my Work Permit and everything its perfect, but my fiance it´s still in Mexico and I was wondering if he can came here to Canada with a tourist visa and here apply for a Work Permit directly with the person who is going to make the contract. Is that posible?
Thank you.

In theory, yes. This assumes that he receives visitor admission and does still require that the work permit application be processed at a visa office outside Canada, even if he is temporarily resident in Canada at that time.