The Italian international was delighted to be joining the Blues, he told Everton's website: "I am very glad to be here because Everton showed so much confidence in me and that is why I am happy to be here."
Everton boss David Moyes said: "He played nearly 50 games for Roma last year and was in the Italian squad that went to the European championship.
Everton borrow a Ferrari
We are talking about someone who has got decent quality, but the biggest thing will be adapting to life in the Premiership."
Ferrari may make his debut at left back tomorrow against Fulham, if his international clearance is processed before midnight tonight.
Ferrari may make his debut at left back tomorrow against Fulham, if his international clearance is processed before midnight tonight.