The 36-year-old made his Roma debut in 1993 and has been rewarded with a new deal in recognition of his performances and commitment to the club over the past two decades.
Totti has started all three games in Serie A this season - scoring in Monday's 3-1 victory over Parma - as Roma have started the campaign with three wins out of three.
The Italy international forward has made over 500 appearances for Roma, winning Serie A in 2000-01, and he spoke of his pride at extending his career at the Stadio Olimpico.
"I thank the club for giving me the opportunity to wear still the only link that I have always loved and cheered," he said. "I have two more years of responsibility and I know that in these two years will do great things together
"A favorite memory? 17.06.2001 (when Roma won the title), as if it were today. The memories I still have to create? Hopefully even better.
"This year we started on the right foot, we are a good team and our coach is really competent."
Club owner James Pallotta expressed his delight that the club captain had signed a new deal, as he said: "I'm honored that Francesco Totti is staying here and I'd like to toast to a great future for Roma and Francesco."
Totti, capped over 50 times for his country, is expected to captain Roma against their city rivals Lazio on Sunday.
