Achieving Maslahah is one of the sharia objectives. The lack of clear evidence from Alquran and Al-sunnah concerning financial transaction makes its role very important. This paper aims to explain the concept of Maslahah and opinion of scholars of Maslahah as one of Islamic sources and their evidences. This paper also mentions legal maxim that has strong relationship with Maslahah. It also explains some of the application of Maslahah in Financial Transaction. The methodology of this paper is through qualitative research based on relevant literatures on Maslahah. The general finding of this paper shows that there are three categories of Maslahah in the application of financial transaction