It is foreseen that the Internet of Things (IoT) will comprise billions of connected devices, and this will make the provisioning and operation of some IoT connectivity services more challenging. Indeed, IoT services are very different from legacy Internet services because of their dimensioning figures and also because IoT services differ dramatically in terms of nature and constraints. For example, IoT services often rely on energy and CPU-constrained sensor technologies, regardless of whether the service is for home automation, smart building, e-health, or power or water metering on a regional or national scale. Also, some IoT services, such as dynamic monitoring of biometric data, manipulation of sensitive information, and privacy needs to be safeguarded whenever this information is forwarded over the underlying IoT network infrastructure. This paper discusses how software?defined networking (SDN) can facilitate the deployment and operation of some advanced IoT services regardless of their nature or scope. SDN introduces a high degree of automation in service delivery and operation—from dynamic IoT service parameter exposure and negotiation to resource allocation, service fulfillment, and assurance. This paper does not argue that all IoT services must adopt SDN. Rather, it is left to the discretion of operators to decide which IoT services can best leverage SDN capabilities. This paper only discusses managed IoT services, i.e., services that are operated by a service provider.