The England international joins chelsea from Leicester City, the club where he began his professional career.
On his move to Stamford Bridge, Chilwell said: ‘I am delighted to be joining Chelsea at this very exciting time for the club. I’m looking forward to being a part of this young, dynamic squad led by Frank Lampard as we challenge for honours next season. I can’t wait to get started and hopefully it won’t be long before we’re playing in front of the Chelsea fans at Stamford Bridge.’
Chelsea director Marina Granovskaia added: ‘We are very pleased to have completed our third addition to our exciting squad for the coming season. Ben brings plenty of top-level experience playing in the Premier League, Champions League and at international level, despite his young age.
‘We are confident Ben will adapt very quickly to being a Chelsea player and with the fixture programme for 2020/21 especially busy, he is a fantastic addition to the squad needed to challenge for honours.’
Chilwell is one of the most established and promising full-backs in the Premier League having made over 120 appearances for Leicester City since his debut as an 18-year-old back in October 2015.
An England international who likes to attack from left-back, contributing with assists and the occasional goal, Chilwell is equally adept at the defensive side of the game and has been a key figure in Leicester’s increasingly resilient rearguard in recent years.
In his most recent campaign at the King Power Stadium he featured on 33 occasions for Brendan Rodgers’ side, scoring three goals as the Foxes finished fifth.