Running a terrorist organisation can be expensive, especially if a group engages in a prolonged campaign or assumes state functions in areas under their authority. This chapter explores how terrorism is financed, and investigates the several most widely used methods of raising funds. It shows that many sources of funding provide additional, non-monetary rewards. There are five main sources of finance open to terrorists: legitimate investments, state sponsorship, donations/extortion, charities, and crime. The chapter reviews how terrorist financing has adapted to counter-measures and globalisation. As organised crime can be important for financial, symbolic and operational goals, it interrogates the relationship between terrorism and organised crime by exploring Makarenko's crime–terror continuum. The chapter concludes by challenging the belief that ideology prevents the formation of alliances between criminals and terrorists, or the development of hybrid crime/terror groups.