The deal includes a €8million option to buy, while Barca will pay a €2m loan fee for Boateng, to feature for them the remainder of the season.
The 31-year-old will be presented on Tuesday morning, with a private contract signing set to be followed.
There would also be a photo session on the Camp Nou pitch and a press conference at noon.
A statement on the club’s official website reads:
“Kevin-Prince Boateng is a player who will surely adapt quickly to the team. With experience of playing in four of the biggest leagues in Europe, the Premier League, the Bundesliga, Serie A and La Liga, he is a man who has scored goals wherever he has been.
“Furthermore, Boateng is a player who versatile to a fault. During his time with Las Palmas with Quique Setién as coach he played as an out and out striker, a typical number ‘9’. However, he is also able to play further back as he did at AC Milan, scoring twice against Barça in his time with the Rossoneri.
“His ability to bring people into the game means he is excellent at playing behind the main striker.”