Chelsea paid Manchester City an initial £40 million to acquire Cole Palmer, a forward for the England Under-21 national team.
The 21-year-old has signed a seven-year contract that includes a further one-year option for £2.5 million.
Palmer, a product of the City youth system, helped England win the European Under-21 Championship earlier this summer.
“I’m excited to get started, and it feels great to sign,” he exclaimed.
I’m excited to have the opportunity to share my skills and contribute to an exciting project, thus I’ve decided to join Chelsea.
“We have a young and hungry team, and I think we have a shot at winning.”