The highly-rated centre-half made a single appearance for Antonio Conte this term, coming off the bench in the League Cup victory over Nottingham Forest back in September.
Over the course of his Career in west London he has made just a single Premier League appearance, back in 2006 against Aston Villa.
The 20-year-old has been at Stamford Bridge since the age of eight and has won multiple UEFA Youth League and FA Youth Cup medals.
Clarke-Salter was also part of the U20 World Cup squad with England in June and has since been promoted to the U21 set-up.
The man John Terry once described as his long term replacement, was jubilant at making the switch to the Stadium of Light and manager Chris Coleman shared his delight:
"Jake is exactly the type of hungry young player I have spoken about and he has shown me just how keen he is to come to here and play in front of our supporters."
Clarke-Salter revealed that Coleman was the main reason he agreed to make the switch, claiming his "mind was made up then," after receiving the call from the manager.