The reigning U.S. Marathon champion and the top American finisher in the 2024 Paris Olympics will once again set his sights on a potentially record-breaking finish at the 2025 Bank of America Chicago Marathon.

Marathon organizers on Thursday announced Conner Mantz will return to Chicago streets in an attempt to break the American record, currently held by Khalid Khannouchi with a time of 2:05:38, set in 2002.

"With his performances in 2025, Mantz has shown he is the most legitimate threat to Khannouchi’s place atop the all-time list in more than a decade," the Chicago Marathon said in a release.

He's already broken an 18-year-old half marathon record by running the Houston Half Marathon in 59:17. He then went on to finish fourth in the Boston Marathon with a time of 2:05:08, fighting a headwind on the non-record eligible course.

Now, he said he feels ready to take on the challenge.

“I feel ready to run at that pace,” said Mantz. “After Boston, where I finished with guys who have run 2:02 and 2:03, it doesn’t feel like a stretch to say I can run 2:05:30 on a looped, flat course.”

Mantz made his debut in the Chicago race in 2022. He finished seventh that year with a time of 2:08:16, then returned the next year to beat that time by 29 seconds, making him the fifth fastest American marathoner of all time.

“I want to get the American record in the U.S.,” Mantz said. “I’m well prepared. On the right day, you can do something pretty special in Chicago.”

Experts believe he could do it.

“Conner has reached a level where he can make and achieve big goals,” said Ed Eyestone, Mantz’s coach and the 1994 Chicago Marathon runner-up. “Chicago is the perfect location for him to combine his consistency and confidence in a build that will hopefully culminate in the American record.”

Khannouchi's record has stood for 23 years. He first set the American record in Chicago in 2000 before beating his own time two years later in London. Khannouchi is expected to be in Chicago in October to cheer Mantz on in his goal.

“Holding the American record all of these years has meant the world to me,” Khannouchi said. “But, I don’t think it will be a bittersweet moment for me if the record gets broken this fall. We will all be rooting for Conner.”

A men's American record would mark the latest in a string of record-breaking finishes in Chicago.

In the last three years, the women's American record, the men's world record and the women's world record have all been set at the race.

“The Bank of America Chicago Marathon is a great American race in a great American city and it's where the American record belongs,” said Executive Race Director Carey Pinkowski. “I look forward to seeing Conner run into Grant Park with time to spare so he can celebrate with all of the fans cheering him across the finish line."

The 2025 Bank of America Chicago Marathon is set to take place on Oct. 12.