The Premier League have confirmed that the USA international has left the club after spending nine years at Craven Cottage.
Ream signed a contract extension in December 2023, but The Athletic are reporting that Fulham have allowed him to depart on a free transfer due to his years of service.
Ream told the club's website: "When I walked through the Motspur Park doors in 2015, I would have never predicted what the following nine years would bring.
"In all my conversations with the people around the club, it was clear this organisation and city were the right places for my family, and I to continue our journey.
"I'm here to win, and I'm looking forward to getting to know the team as we prepare for a key stretch of matches that will propel us toward the playoffs as we fight for our first trophy."
Fulham bid farwell to long-serving defender
Ream leaves Fulham after featuring in 312 matches in all competitions and helping the club win promotion from the Championship on three occasions.
Fulham vice-chairman Tony Khan said: "All of the Fulham supporters around the world and everyone at the club are grateful to Tim Ream for his many years at Craven Cottage!
"Tim is a Fulham legend, an indelible presence in our defence, an unparalleled professional, and a great friend to so many of us at the club. We'll miss him, but he goes with our best wishes for the rest of his wonderful career.
"The club's supporters, staff and his friends will always welcome him back at Craven Cottage with open arms, and Tim Ream will be forever Fulham."
The 36-year-old defender returns to the MLS for the first time since leaving New York Red Bulls for Bolton Wanderers in January 2012.
The experienced centre-back has signed a contract with Charlotte until 2026, with an option to extend by a further 12 months.
Dean Smith's side are currently sitting in sixth place in the Eastern Conference after collecting 37 points from 25 matches.
What does Ream's departure mean for Fulham?
Ream has become the second centre-back to leave Fulham this summer after Tosin Adarabioyo departed at the end of last season.
The Cottagers recently strengthened Marco Silva's defensive options with the addition of Jorge Cuenca from Villarreal.
The West London club will now be keen to recruit another central defender to fill the void created by Ream's departure.
Fulham have recently been linked with a potential move for Aston Villa's Diego Carlos, who has two years left to run on his current contract.