This chapter examines the origins, definitions, and principles of feminist criminology. It begins with a discussion of the main theoretical traditions that underpin feminist criminology, namely liberal feminist theory, radical feminist theory, Marxist feminist theory, and socialist feminist theory. It then considers feminist epistemologies such as feminist empiricism, standpoint feminism, and postmodern feminism, as well as the intersections between gender and other structures of disadvantage. It also evaluates the interrelationships between gender and crime by addressing feminist explanations of female crime and masculinities studies of male crime, along with the role of gender in the criminal justice system. The chapter concludes by analysing feminist criminologists' criticisms of what they describe as the androcentricism of mainstream criminological theories as well as some of the key criticisms against feminist perspectives on gender and crime.