The current chapter gives a general overview of Estonian legal system by its historical development, describing the most relevant periods of the ancient Estonian legal society, influences to the local law by the foreign powers and the contemporary impact and position of EU and international law to the current Estonian legal system, and its judicial system. The legal policy of implementation and interpretation of international and supranational law have been explained through the approaches derived from evolving constitutional legal traditions. Estonia is famous for its e-governance and so-called e-law, which is often presented as characteristics of Estonian legal society where the most of the public services offered and used on-line. As the law of e-Governance is not framed as one branch of law, the chapter focuses on e-identity, data protection, ICT law and other relevant legal regulation fields and issues. The last part of the chapter is dedicated to the legal regulation of state security as a part of a legal system. In recent years Estonia has promoted the enhanced international cooperation in state security and the last section provides corresponding overview of the international and EU level legal instruments and their application in Estonia.