Billions of IoT devices will be deployed in the near future, taking advantage of the faster Internet speed and the possibility of orders of magnitude more endpoints brought by 5G/6G. With the blooming of IoT devices, vast quantities of data that may contain private information of users will be generated. The high communication and storage costs, mixed with privacy concerns, will increasingly be challenging the traditional ecosystem of centralized over-the-cloud learning and processing for IoT platforms. Federated Learning (FL) has emerged as the most promising alternative approach to this problem. In FL, training of data-driven machine learning models is an act of collaboration between multiple clients without requiring the data to be brought to a central point, hence alleviating communication and storage costs and providing a great degree of user-level privacy. We discuss the opportunities and challenges of FL for IoT platforms, as well as how it can enable future IoT applications.