Raikkonen, who will leave Lotus to join Ferrari as the replacement for Felipe Massa next season, won the 2007 world championship during his first stint with the Italian team but left just two years later after apparently growing disillusioned with the sport.
Two indifferent years in rallying reignited his passion for F1, and he has impressed since returning at the start of 2012, winning two races and finishing third in the drivers' championship last season.
"I am really happy to be returning to Maranello where I previously spent three fantastic and very successful years," Raikkonen told ferrari.com.
"I have so many memories of my time at Ferrari, memories which have stayed with me these past years, first and foremost, winning the world championship title in 2007, which was really unforgettable."
The move pairs the rapid Finn with two-time world champion Fernando Alonso in what will arguably be the strongest driver line-up on the grid.
"I can't wait to be driving a Prancing Horse car again and to reacquaint myself with so many people with whom I had such close links, as well as working with Fernando, whom I consider a great driver, in order to bring the team the success it deserves," Raikkonen added.
Raikkonen contested 52 grands prix for Ferrari between 2007 and 2009, winning on nine occasions. Six of those victories came in his first season as he beat McLaren duo Alonso and Lewis Hamilton to the world title by a single point.
However, he failed to replicate his 2007 performances in the two seasons that followed and negotiated a release from his contract a year early at the end of 2009, with the Scuderia bringing in Alonso as his replacement.
After returning to the sport with Lotus Raikkonen finished in the points in 19 of his first 20 races - including a win in Abu Dhabi - as he finished the 2012 season in third place in the drivers' standings.
He began his 2013 campaign with victory in Australia, and has finished in second place five times in 11 races since.
Ferrari team principal Stefano Domenicali welcomed the return of Raikkonen, who remains the only man other than Michael Schumacher to win the drivers' title for the team since 1979.
"I am delighted to welcome back to Kimi in the Scuderia with whom he was crowned world champion," said Domenicali.
Raikkonen saw off the challenge of both Massa and Sauber's Nico Hulkenberg to land one of the most coveted seats in F1 and is sure to prove a thorn in the side of Alonso, who has enjoyed undisputed number one status alongside Massa since joining the team.
Alonso famously left McLaren after just one season after becoming frustrated with having to share number-one driver status with then-rookie Hamilton, and how the Spaniard copes with Raikkonen's arrival will be closely scrutinised next year.
Alonso did at least have warm words for Raikkonen on Wednesday, saying: "I'd like to welcome my new travelling companion: together, starting next year, we will have to tackle a very demanding technical and racing challenge."
Raikkonen, who began his F1 career with Sauber in 2001 before spending five seasons at McLaren, had been linked with a move to world champions Red Bull but was overlooked in favour of Australia's Daniel Ricciardo.
Ferrari's decision to part with Massa ends the Brazilian's eight-year stint driving for the Prancing Horse, during which time he lost out on the 2008 world title by a single point and suffered a fractured skull in a freak accident in qualifying for the 2009 Hungarian Grand Prix.
Massa, who has made 184 starts for Ferrari - winning 11 times - has indicated he is keen to continue in F1 next season and has been touted as a possible replacement for Raikkonen at Lotus.
Domenicali paid tribute to Massa, saying: "I want to thank Felipe with all my heart, on behalf of our fans around the world, for the extraordinary work he has done for the team in all these years."
Alonso added: "I want to thank Felipe for all the support he has given me and the team during this journey we have made together over all these years.
"Come the end of the season, it will not be easy to say goodbye to a team-mate like him."
Meanwhile, Lotus reacted to news of Raikkonen's departure with a bizarre message on Twitter, which featured a graphic image of two rabbits mating and the accompanying message: "So #Kimi is off to #Ferrari for 2014; it hurts a little bit... #F1".