It has been confirmed by the UFC that Brock Lesnar will return to the octagon and will compete at UFC 200 at the T-Mobile Arena July 9th in Las Vegas, Nevada. An opponent has yet to be confirmed by the UFC but it is expected to be confirmed within the next coming days. There has been speculation on who it could be with a a few names being thrown out there but nothing official.
WWE also confirmed the news on their twitter/website stating that Lesnar is still under contract to the WWE but they have granted him a one fight opportunity to compete at UFC 200. They also confirmed that Brock Lesnar will be returning to the WWE for their summer event Summer Slam which takes place in August.