The last decade in Indonesia has seen the emergence of localized militia groups. In Bali, these groups are now particularly prolific. Conventional wisdom in international relations thought is that these organizations constitute a threat to the authority of the state (its monopoly on the legitimate use of force) and may require national security measures to deal with them. Yet these organizations ultimately define their own role in terms of the provision of security, claiming that they act to preserve or advance core values of their communities. In this sense, their security role with reference to the state is ambiguous: they often enjoy legitimacy at the local level and perform important security functions for their local communities, even while constituting an alternative site of security practice and challenging the (exclusive) security role of the Indonesian state. Drawing on ethnographic research, this article examines these actors as security agents and employs a framework of security contestation to make sense of the manner in which they engage with and redefine the provision of security in Bali. In this context, the emergence and practices of Balinese militia groups challenge the way we view non-state actors in the security space and, more generally, the way we conceive security agency in international relations.