The news emerged after a number of her fellow 2009 housemates left tributes on social networking sites.
Lisa Elizabeth Wallace posted on Facebook: "Would like to offer my condolences to Sophia brown from bb10s family and friends in their very sad loss. Sophia was a ray of sunshine. I am so glad to of had the pleasure of spending time with her in the bb house.
"Sophia, you were an angel on earth, who always could make me laugh. I know that God would have made you an angel in heaven too. You're expressions and wit will always be something that I will remember forever. The laughs we had I will treasure always. RIP angel. x x x x x never forgotten x x x"
Karly Ashworth wrote on Twitter: "#RIP to Sophia Brown who was also on my series of Big Brother. Such sad news. My thoughts are with her family and friends. X"
Sophie Reade said: "Devastated to hear the news about sophia, such an amazing lady and a pleasure to known her. Cant believe it #RIP"
Victor Ebuwa, who took part in Big Brother 5, commented: "R.I.P. Sophia Brown (Big Brother 10) I only met you a few times but i could tell u were a lovely & wonderful person. You will be missed....."
Big Brother announcer Marcus Bentley added: "Such very sad news about BB 10 housemate Sophia Brown - god bless Sophia xx"
Though her cause of death is currently unknown, the 4ft 11in reality show contestant suffered from Lupus - a disease affecting the immune system - since she was a young child.
London-born Brown - who worked as a bank assistant - was evicted from the Big Brother house on the ninth day following a heated row with Saffia Corden.
Shortly before entering the Big Brother house, Brown said that scoring an A* in GCSE English was the proudest achievement in her life.
Watch Sophia Brown bow out of Big Brother 10 below: