The defenders have been rewarded for their progress last season with improved deals.
Belezika, 18, has played four times for the first team while 20-year-old Brown, who joined from Sheffield United last summer, made 29 appearances in his debut campaign for Latics.
Manager Lee Johnson told the club website: "The improved contract terms reflect how highly we value both players.
"They weren't earning a fortune and this is part of making them responsible adults and helping them develop both as men and footballers."
- Sports & Recreation
- Sheffield United