The 18-year-old, who is due to be in the squad for tomorrow's clash at Gloucester City, has joined the Bucks on a youth loan.
Ravenhill made his first team debut for League One Doncaster last season when he featured in the first round of the FA Cup.
The son of former Rovers midfielder Ricky Ravenhill, he has also featured for them in the Papa John’s Trophy and trained with the senior squad on multiple occasions last season.
Ravenhill met his new Bucks team mates at training on Thursday evening.
His move to the New Bucks Head is his second loan of the season – with the midfielder having spent time with Matlock Town earlier in the campaign.