This chapter examines UNCLOS tribunals’ contribution to the development of the law on maritime entitlement and maritime delimitation-two distinct but related concepts. The chapter first analyses and assesses the extent to which UNCLOS tribunals—as the first international tribunals to deal with questions relating to the entitlement to a continental shelf beyond 200 nm and entitlement from insular features—have contributed to clarifying the legal ambiguities concerning these two issues. The chapter then analyses UNCLOS tribunals’ decisions relating to maritime delimitation within and beyond 200 nm, with a focus on examining the convergences and divergences in UNCLOS tribunals’ application of the established three-stage approach within 200 nm and on assessing the contribution of UNCLOS tribunals to clarifying the legal ambiguities concerning the delimitation of the continental shelf beyond 200 nm.