The Wales international, who has 11 caps for his country, has joined the npower Championship club on an emergency loan until January 3.
The classy midfielder is widely regarded as one of the most exciting young prospects in the Barclays Premier League.
He has made more than 50 appearances for Arsenal and has recently returned after a nine-month lay-off with a broken leg.
Ramsey launched his career with Cardiff, where he was a team-mate of Forest defender Chris Gunter, and he became the club`s youngest player when he made his debut at the age of 16 years and 124 days.
He made just 21 first-team appearances for the Bluebirds before moving to Arsenal in the summer of 2008.