Embodiments of systems and methods for DNS leak prevention and protection are disclosed herein. In particular, certain embodiments include a local DNS protection agent installed on a system and an associated trusted external DNS protection server. The DNS protection agent prevents DNS leaks from applications on the system such that all DNS requests from the system are confined to requests from the DNS protection agent to the associated DNS protection server. As the DNS leak prevention provided by the DNS protection agent stops applications on the system from circumventing the DNS protection server, all DNS requests originating from the system remain under the control of the DNS protection server and thus desired DNS protection (e.g., as implemented on the DNS protection server) may be maintained. Certain embodiments prevent applications from using certain DNS security protocols, such as DoH and DoT, without going through the DNS protection agent.