UFC president Dana White confirmed the news to the Los Angeles Times on Tuesday. No venue was announced.
Jones initially declined to meet Sonnen on eight days' notice after Dan Henderson was forced off a Sept. 1 card with a knee injury.
Following Jones' refusal, Zuffa, the Las Vegas-based promotional company that owns and operates UFC, opted to cancel UFC 151, a first during almost 12 years of business.
Jones (17-1) instead agreed to fight Vitor Belfort on Sept. 22 in Toronto, where he retained the title via fourth-round submission. Early in the fight, however, Belfort secured an armbar that hyperextended the champion's right arm before the submission was denied. As of two weeks ago, Jones' elbow had not fully recovered, necessitating the April date, White told the Los Angeles Times.
Sonnen (27-12-1) is best known for two contests against UFC middleweight champion Anderson Silva. The Oregonian fell short of defeating Silva in July, suffering a second-round technical knockout.
Two years earlier, the strong wrestler pushed Silva into the fifth round before succumbing to a triangle choke.
Sonnen was assigned to face Forrest Griffin at UFC 155, Dec. 29 in Las Vegas, before being moved to face Jones. The contest with Griffin would have been Sonnen's first at light heavyweight since he debuted in the UFC in 2005.
Griffin is healthy, a representative for the former light heavyweight champion told ESPN.com. He expects to participate on the main card of UFC's year-end event in Las Vegas, which is headlined by a heavyweight title showdown between Junior dos Santos and Cain Velasquez at the MGM Grand Garden Arena. No opponent has been named.
Henderson, a former two-division Pride champion, did not immediately respond via text when asked to comment on the Jones-Sonnen matchup. On Twitter, he expressed displeasure with being passed over.
"I guess I should just quit training to win fights and to be exciting for the fans" and instead focus on talking trash, he wrote to White.
A master self-promoter, Sonnen has taken shots at Jones in the media and, especially, on Twitter, beginning in the weeks prior to the cancellation of UFC 151. Jones expressed distaste for Sonnen by suggesting he didn't deserve to fight for the belt because it would "delegitimize" the championship. The champion, however, recently expressed a change of heart.
"The more I realize how bad the fans want to see me fight Sonnen the more I'm beginning to disregard whether he deserves it or not," Jones tweeted last Thursday.
Sonnen jumps to the top of the contender list at 205 despite the existence of other potential opponents.
A Dec. 8 showdown in Seattle between Mauricio Rua and Alexander Gustafsson was billed as a potential No. 1 contender fight. Henderson, who secured a shot at the light heavyweight belt after beating Rua in one of the best fights of 2011, hopes to return to action by the start of 2013.
Leading up to the spring pay-per-view fight, Jones, 25, and Sonnen, 35, will serve as coaches for the latest installment of "The Ultimate Fighter" on FX. The long-standing reality show begins shooting Oct. 29 in Las Vegas and features fighters competing at 185 pounds. The series hits television sets in January, eight years after debuting on Spike TV. Since moving to FX in 2012, ratings have suffered, hitting an all-time series low last week with 624,000 viewers.
ESPN.com's Brett Okamoto contributed to this report.