Coach Mark Richt informed the press of the injury during his Sunday teleconference.
"Marlon, unfortunately, has a torn ACL, so his career at Georgia is over," Richt said. "We are very sad that it happened for Marlon and for Georgia, too"
Brown is the second Georgia receiver to fall victim to an ACL injury this season. Micheal Bennett tore his ACL during practice in early October.
Richt said sophomore Chris Conley and redshirt freshman Justin Scott-Wesley "will have some work."
Richt said the news of the injury was hard to take.
"It's a hard thing to swallow right now."
He ruled out playing freshman Blake Tibbs, who is redshirting this season.
"I'm not interested in playing Blake," Richt said. "Someone would have to convince me of that."