Callaway, 20, was a passenger in a black Mercedes SUV when Gainesville Police Department officers stopped the vehicle driven by Kendrick Williams, 40. The police report said officers smelled marijuana in the car and then found 7 grams of the drug in Callaway's pocket during a search. Williams also was found with marijuana.
Callaway and the driver claimed ownership of the drugs, according to the police report. Callaway is scheduled to appear in court June 6.
"Obviously there was some news that came out today about Antonio that, guys, I'm just really disappointed," Florida coach Jim McElwain told reporerts, according to 247Sports. "I'm aware of it and everything, and we'll handle it accordingly. Just really disappointed.
"At the same time, there's another opportunity to learn. There's another opportunity to educate. We'll get it handled."
It is not the first time that Callaway, the team's top playmaker, has run into problems off the field.
After being suspended amid sexual battery allegations last spring, he was fully reinstated to the team in August after an independent hearing officer found Callaway not responsible of sexually assaulting a female student in December 2015.
During a student code of conduct hearing for those allegations, Callaway had acknowledged that he "was so stoned [he] had no interest in having sex with anyone." After that admission, McElwain had said there would be consequences if Callaway's marijuana usage "becomes habitual."
"If there are some issues, find help," McElwain said in August. "If it becomes habitual, then there are some consequences. ... If it becomes one of those deals through the counseling hasn't worked and that kind of stuff, then there will be some harder consequences, and yet those haven't come up yet."
Callaway caught 54 passes for 721 yards and 3 touchdowns during his sophomore season for the Gators. Overall, he has 89 receptions for 1,399 yards and 7 TDs in two seasons.
The Gators open the 2017 season against the Michigan Wolverines at AT&T Stadium in Arlington, Texas, on Sept. 2.
The Associated Press contributed to this report.