Central midfielder Vidal has penned a two-year deal with the option of a third season.
— Inter (@Inter) September 22, 2020
The Nerazzurri will pay no initial fee and €1m in future variables for Vidal, 33, who is returning to Italy after five years.
After more success in Germany, including three league titles, the Chilean moved to Barcelona in 2018.
Vidal made 96 appearances for Barca, scoring 11 goals and contributing 10 assists.
At Inter, Vidal reunites with Antonio Conte, who he worked with during his time at Juventus.