The 29-year-old Filipe Luis was one of three Atletico players, alongside Diego Costa and Thibaut Courtois, to join Chelsea last season. Atletico said Tuesday it has reached an agreement for his return.
Atletico said it was reinforcing its squad and expected him to adapt quickly as "he already knows our club and our way of playing."
Filipe Luis first joined Atletico from Deportivo La Coruna in 2010, and played 184 times.
He made 26 appearances with Chelsea, and helped it win the Premier League and League Cup titles, but he was not able to displace first-choice defender Cesar Azpilicueta.
This story has been corrected to show that the player's name is Filipe, not Felipe.