Methods and apparatus for providing scalable private services in service provider networking environments. A service provider that provides a large, public, multi-tenant implementation of a web service to multiple customers via a public API endpoint may allow a customer to request the establishment of a private implementation of the service. In response, a service private instance may be automatically and/or manually established for the customer that provides a private API endpoint to the service and that is at least in part implemented on single-tenant hardware that is not shared with other customers. The service private instance may initially be implemented as a relatively small scale and possibly limited implementation of the service when compared to the service public instance. As the needs of the customer grow, the service private instance may be automatically and/or manually scaled up from the initial implementation.