Robert Daley was found stabbed to death at an address in south London, on Friday.
The teenager, who was arrested last night, will appear at Sutton Youth Court today.
A 14-year-old girl appeared in the same court on Tuesday charged with the killing.
Scotland Yard said a 16-year-old girl also arrested last night was bailed to return in May.
The Crown Prosecution Service confirmed Mr Daley had been investigated over allegations of sexual offences, but the case was dropped.
An 18-year-old man was arrested earlier and was bailed to return in May.