Jones, 49, was charged over his alleged role in a scheme that prosecutors say provided inside information on injuries and game absences to bettors between December 2022 and March 2024.
In one instance, he shared that LeBron James would not play due to injury in a Los Angeles Lakers game against the Milwaukee Bucks before that information was made public.
Jones initially denied the charges but pleaded guilty to a single count of conspiracy to commit wire fraud in a New York court. Sentencing is scheduled for January 2027.
"I would like to sincerely apologise to the court, my family, my peers and also the National Basketball Association," he said during the hearing, according to US media.
Jones is the first of six defendants to plead guilty in the case, which includes Miami Heat guard Terry Rozier.
Federal prosecutors plan to bring further charges against Rozier, alleging that he "solicited and accepted a bribe," The New York Times reported.
Jones was expected to plead guilty later Tuesday in a second, separate case involving a national network of mafia-linked, rigged poker games.
Around 30 people participated in the scheme, which used highly sophisticated cheating equipment, including X-ray tables, and Jones allegedly used his fame to lure in victims.
Jones had a modest playing career across 11 different teams, notably the Cleveland Cavaliers from 2005 to 2008, where he played alongside four-time NBA champion James.
He later became an assistant coach, working again for the Cavaliers from 2016 to 2018 during James's second stint in Ohio.
Jones served as James's personal coach during the 2022/23 season after the star joined the Lakers, without being employed by the team.