This chapter identifies the origins, content, and operation of federal jurisdiction in Australia. In the United States the creation of federal jurisdiction was the necessary concomitant of the establishment of the judicial arm of federal government. The same could not be said of the conditions for Australian federalism. Federalism Australian-style did not require a federal system of courts. Further complicating the issue was the ‘autochthonous expedient’: the facility provided to Parliament for the use of State courts to exercise federal jurisdiction. Hence the chapter also seeks to suggest that the discordance between the concept and purpose of federal jurisdiction left the High Court with the challenging task of conceptualizing ‘judicial federalism’. In executing that task, High Court jurisprudence has presented differing conceptions of the place of State courts within the federal judicial system.