The 37-year-old won 117 caps and scored 21 goals as a player for the Azzurri.
"I'm proud to start this new career with the national team and I thank both president [Gabriele] Gravina and coach Mancini for the trust and the opportunity," De Rossi told the FIGC's official website.
"It will be exciting to return to Coverciano, which for me means coming back home and find many former colleagues and friends in the staff and the group. I can't wait to get started."
Italy manager Roberto Mancini added: "I'm very pleased that Daniele joins our group."
"I'm sure he will be able to give the lads an important contribution and I hope that his first experience will be useful for the future."
Italy play three FIFA World Cup qualifying games against Northern Ireland, Bulgaria and Lithuania in the upcoming international break. They are in the same group with Switzerland, Turkey and Wales at this summer’s EURO 2020 tournament.
At the age of 22, De Rossi was the youngest member of Italy’s FIFA World Cup winning squad at Germany in 2006.
De Rossi made 616 appearances for AS Roma after making his debut in 2001, scoring 63 goals and winning two Copa Italia trophies for the side.
Only Francesco Totti, who made 786 appearances for Roma, has played more times for the Serie A club than De Rossi.
