Jones had two years and almost $21 million remaining on his contract. The $66 million extension also increases his guaranteed money to $66 million, with $64 million due at signing, sources told ESPN's Adam Schefter and Chris Mortensen.
"I love this city, and I'm committed to being a Falcon for life," Jones said in a statement.
"There are a handful of elite receivers and Julio is certainly a part of that group, not only because of his production on the field but his leadership off the field and in the locker room," general manager Thomas Dimitroff said in a statement. "Julio has been a cornerstone of our organization for several years and we have always intended for that to continue for years to come."
The deal makes Jones the NFL's highest-paid wide receiver in terms of guaranteed money. Jones will collect 97% of the contract at signing, surpassing the previous record for a non-quarterback (Trey Flowers, 74%).
It also means Jones, a six-time Pro Bowl selection, will be in the lineup for the Falcons' season opener against the Minnesota Vikings on Sunday.
Both team owner Arthur Blank and Dimitroff vowed to prioritize an extension for Jones after the team adjusted his contract last year, giving him an additional $2.9 million for 2018.
"He's been such a huge part of my career up until this point," Falcons quarterback Matt Ryan said in a statement. "Just so consistent. His production is through the roof. Obviously, he's an unbelievable teammate. He's a great friend.
"I'd love to play with him my entire career. He's one of the absolute best to ever do it. [I'm] certainly lucky to have played with him for as long as I have, and I hope there's a lot more in the tank for both of us."
The latest deal for Jones could not be reached until after July 27 -- 12 months following his last renegotiation -- per collective bargaining agreement rules.
Jones expressed trust for the organization throughout the process. His decision not to participate in the voluntary offseason program was not believed to be contract-related. Jones showed up for mandatory minicamp but did not participate while rehabilitating from having a bunion removed from his foot.
He also reported to training camp on time, although he has spent most of camp rehabbing on a side field.
Blank promised to reward Jones, defensive tackle Grady Jarrett and linebacker Deion Jones leading into the 2019 season. Jarrett received a four-year, $68 million contract ($38 million guaranteed), and Deion Jones received a four-year, $57 million extension ($34 million guaranteed).
Julio Jones downplayed how other top receivers could affect his negotiations, although it is believed to have played a role.
Jones, the fastest in NFL history to 10,000 receiving yards (103 games), holds eight franchise records. He enters the 2019 season with five straight seasons with at least 80 catches and 1,400 receiving yards. His 10,731 receiving yards are 133 shy of surpassing Roddy White for the franchise record.
The Falcons selected Jones with the sixth overall pick in the 2011 draft out of Alabama. His 96.7 receiving yards per game ranks as the highest average in NFL history.
Jones' extension follows a five-year, $150 million extension signed by Ryan last year. The next offensive player to receive an extension is likely to be tight end Austin Hooper, who was named to his first Pro Bowl last season.