Hobbs Kessler, born on March 15, 2003 in Ann Arbor, Michigan, began his athletic journey at Planet Rock gym, where he trained alongside his childhood friend and now fellow Olympian, Zach Hammer. He graduated from Skyline High School, where he made a name for himself as a standout runner. Opting to skip college, Hobbs turned professional immediately after high school, a decision that has led him to break numerous records.

In early October 2023, Hobbs ran the fastest 1500 meters ever recorded by an American on U.S. soil, clocking in at 3:32.61. Earlier in February 2024, he set a personal best time of 3:48.66 at the Millrose Games, placing him fourth on the all-time indoor mile list.