The only time he didn't start Opening Day was in 2016, after former teammate Jake Arrieta won the Cy Young award.
Manager Joe Maddon broke the news to him on Monday morning.
"I've been fortunate enough to do this a few times," Lester said. "It's always a huge honor. ... To be entrusted with that a couple times here and other places, it's just a huge honor to have that on your shoulders and try to get your team off to a good start."
In an era where players don't always live up to long-term contracts, the Cubs feel Lester has been the exception. The team has made the playoffs every season after he signed a six-year, $155 million deal before the 2015 season.
"He's been spectacular," Maddon said. "He's been our rock. I've gained an even greater appreciation for him working side by side."
Lester has emerged as one of the leaders on the Cubs, further cementing his legacy in Chicago. His teammates revere him as much as fans do.
"Jon is one of the most consistent players in our game," pitcher Mike Montgomery said. "He deserves that (Opening Day start). I'm excited to play another season with him."
It's Lester's eighth Opening Day start overall. He took the ball in Game 1 of the season four straight years in Boston, from 2011 to 2014.
Maddon added: "He's a pro's pro."