Chapter 4 explores what constitutes family violence—or domestic violence or domestic abuse, as it is referred to in some jurisdictions. Definitions of family violence vary widely across family violence legislation, the Family Law Act 1975 (Cth), the criminal law, and other types of legislation such as victims’ compensation legislation and migration regulations. The chapter considers whether it is appropriate or desirable to aim for a common interpretative framework for what constitutes family violence across the different legislative schemes under consideration. The chapter also considers addressing key differences in family violence legislation across the jurisdictions—for example by model provisions which contain best practice approaches.