The 63-year-old comedian and veteran Oscar host said Thursday on Twitter that he is hosting this season's Academy Awards "so the young woman in the pharmacy will stop asking my name when I pick up my prescriptions."
"Some of the best moments of my career have happened on the Oscar stage," said Crystal in a later statement from the Academy of Motion Picture Arts and Sciences. "I am thrilled to be back there."
This will be the ninth Oscar stint for Crystal, one of the most popular Oscar hosts of recent years. His last time was in 2004. Only Bob Hope hosted more Oscar shows, with 19 ceremonies between 1940 and 1978.
Academy president Tom Sherak called Crystal "a comic legend and Oscar icon, and it feels good to have him back where he belongs."
The naming of Crystal follows a groundswell of sentiment for his return after he led a tribute to Bob Hope on the 2011 Oscar show for which he received a standing ovation. Crystal said later he was moved by the warm reception and that "it might be fun" to host the show again.
"I think the show needs to change," he said in an interview with The Associated Press in March. "There's too many awards and it has to sort of freshen itself up, and if I can be a part of that, that would be great."
Crystal previously hosted in 1990, 1991, 1992, 1993, 1997, 1998, 2000, and 2004 - some of the most successful shows in Oscar history. The 1998 show was the highest-rated Oscar telecast ever, when "Titanic" sailed away with multiple trophies.
The 2011 ceremony featured the duo of Anne Hathaway and James Franco in an effort to attract younger viewers, but with disappointing results. Steve Martin and Alec Baldwin hosted the year before.
Comedian Eddie Murphy had been chosen to host the Feb. 26, 2012, show, but pulled out Wednesday following the departure on Tuesday of producer and friend Brett Ratner, who left amid criticism of his use of a pejorative term for gay men at a screening of the director's action comedy "Tower Heist," which stars Murphy.
Ratner was replaced this week by veteran producer Brian Grazer, joining co-producer Don Mischer, who was named producer alongside Ratner in August.
"Like so many others, I've been eager to see Billy host again," said Grazer. "It's very gratifying that he agreed to do it with Don and me at the helm."
"With Billy, we're moving forward with one of the greatest hosts in Oscar history," said Mischer. "His return to the Oscars is, in a sense, a celebration."
In an interview prior to the Crystal announcement, Tom O'Neil, editor of the awards website GoldDerby.com, had noted "there would be cheers across Hollywood for Billy's return. That could be the happy ending for this story."
AP Movie Writer David Germain and AP Entertainment Writer Sandy Cohen contributed to this report.