'Welcome home': Roma appoint Ranieri as manager until end of the season
Roma said that Ranieri, who won the Premier League title with Leicester City in 2016, has signed a deal until the end of the season.
The 73-year-old will then "transition into a senior executive role, where he will be an adviser to the ownership on all sporting matters at the club".
"The search for a future coach will proceed over the next months. Claudio will have input in that decision as well," added Roma.
Ranieri agreed to coach Roma for the third time following negotiations in London on Wednesday, after which he was mobbed by fans at Rome's Fiumicino airport.
He replaces Ivan Juric, who was hired in September following the dismissal of former club captain Daniele De Rossi, but was sacked after Sunday's 3-2 home defeat at the hands of Bologna.
Juric's short spell in charge was a disaster, with four wins from 12 matches in all competitions, and the former Croatia international left Roma 12th in Serie A, just four points above the relegation zone.
Ranieri announced the end of his club management career after guiding Cagliari to safety last season.
He told Sky in Italy at the time that he would be interested in a national team job but he has made a comeback to help dig Roma out of a deep crisis.
Ranieri returns to lead Roma out of a crisis for the second time after replacing the sacked Eusebio Di Francesco in March 2019 and helping to secure Europa League qualification.
But he is held in great affection by his fellow Roma fans primarily for his first spell in charge which began a decade before.
He took over from Luciano Spalletti early in the 2009-10 season and led Roma on a thrilling league title challenge with Jose Mourinho's Inter Milan which went to the last day of the campaign.
Ranieri has a baptism of fire as his team travel to Napoli after the international break before then facing Tottenham Hotspur in London and Atalanta at home.
