The Manchester United winger was last month named as the PFA Player of the Year, and Young Player of the Year, following a superb campaign at Old Trafford.
His exploits this term have now been recognised by the critics and he again beat Chelsea striker Didier Drogba into second place.
Ronaldo's United team-mates Ryan Giggs and Paul Scholes occupied the third and fourth spots in the voting.
The Portugal international will receive his award at the FWA Footballer of the Year dinner at the Royal Lancaster Hotel in London on 17th May.
He told the FWA: "I am absolutely thrilled and delighted to win such an important award, it is a real honour."
The 22-year-old, who has recently signed a new long-term contract with the Premiership leaders, was a 'runaway' winner of the award, according to FWA chairman Paul Hetherington.
"After the events of last summer at the World Cup, the vote of the Football Writers' Association shows that what we are all interested in is honouring the best player in the country," said Hetherington.
"There has been no agendas carried over from last summer.
"This was a heavy poll of our members. Cristiano has been a runaway winner and deservedly so.
"We also know we have a player who is absolutely delighted and honoured to receive this accolade."
