Mourinho will replace fellow Portuguese Paulo Fonseca.
Earlier on Tuesday, AS Roma announced that Fonseca will leave at the end of the current season.
Meanwhile, Mourinho has been a free agent following his sacking from Tottenham Hotspur.
He has signed a three-year deal with AS Roma that will see him manage the club until 2024.
Mourinho can’t wait for his next task
After his appointment, Jose Mourinho said that the passion attracted him to sign for the Rome-based side.
He therefore can’t wait to start his next task of managerial career.
“The incredible passion of the Roma fans convinced me to accept the job,” Mourinho said before adding.
“I cannot wait to start next season.”
“Thank you to the Friedkin family for choosing me to lead this great club.”
“After meetings with the ownership and Tiago Pinto, I immediately understood the full extent of their ambitions.”
“It is the same ambition and drive that has always motivated me.”
“Together we want to build a winning project,” Mourinho added.
It should be noted that Mourinho was sacked from Spurs after 17 months in charge.
This was because of a poor second half of the season in which Spurs slipped from top of the table to outside the European places.
Roma expects big
According to AS Roma general manager Tiago Pinto, Mourinho has the capability to enable them compete to the top level.
“When Jose became available, we immediately jumped at the chance to speak with one of the greatest managers of all time,” Pinto said.
“We were blown away by Jose’s desire to win and his passion for the game: no matter how many trophies he has won, his primary focus is always on the next one.”
“He possesses the knowledge, experience and leadership to compete at all levels.”
“We are supremely confident Jose will be the perfect coach for our project, for both our immediate and long-term future,” he added.
Roma have not won Serie A since 2000-01, when Fabio Capello was in charge.
This will be Mourinho’s second stint in Italian Serie A.
His first stint in Italian football was a successful one with Inter Milan that produced four major honours in two years.
He won the Italian Serie A title twice, the second victory forming part of the club’s historic treble in 2009-10 which also saw them claim the Champions League and Coppa Italia.