The 25-year-old son of French World Cup winner Lilian Thuram joins Inter after four seasons with Gladbach during which he scored 44 goals and registered 29 assists in 134 appearances.
Thuram has been capped 10 times for France, having made his debut in the senior team in 2020 and was part of their Euro squad that year. He also played in the World Cup last year, where France finished as runners-up.
“Marcus Thuram is quick. He has always been quick to reach his goals and to overcome any hurdle in his path. To show that he is worth so much more than just the name on the back of his shirt,” Inter said in a statement.
Thuram, who was born in Parma during his father’s spell at the Italian club, was linked to several European clubs before signing with Inter.
Inter, who lost to Manchester City in the Champions League final last month, have already announced the departures of Milan Skriniar, Danilo D’Ambrosio and Roberto Gagliardini from the club upon the expiry of their contracts.