The 32-year-old Scarborough-born schemer, who can play anywhere across the midfield four, began his career at York City before spending three years at Manchester United.
Greening has also played for Middlesbrough and West Brom, and was a fans' favourite at The Hawthorns where he was skipper for most of his spell there.
However, he only made 10 league appearances for the Cottagers last season and his move to the City Ground should ensure him more first-team football.
Greening followed new Forest boss Steve McClaren to Middlesbrough from Manchester United when he took charge at the Riverside in 2001.
He will reportedly cost McClaren around £600,000 this time and is a contender for the captaincy this season following the release of Paul McKenna.
The Liverpool 2013/14 soccer jersey is available for pre-order. The Reds are eager to compete for silver next season.
adidas has added some color to the Predator line with this new colorway. Released on May 17. Be the first to own a pair.
The Juventus jersey for the 2013/14 was released earlier this week. Be the first to wear the colors of the Old Lady.
Bayern Munich are kings of Germany and hope to be crowned kings of Europe at Wembley later this month!
Borussia Dortmund hears Wembley Calling and are headed to London for the Champions League final.
Ajax has released their away soccer jersey for the 2013/14 season. Get in the Gear.
The new PUMA evoSPEED 1.2 FG. A great new soccer cleat with classic look and first time for PUMA to be on the cleat.
Chelsea won the Europa League on Wednesday. The Blues defeated Benfica 2-1 on injury time goal from Ivanovic.
One of the top soccer cleats for control the Nike CTR360 will not let you down on the field in tight spaces.
The push for more color on their cleats, adidas has added the infrared colorway to the adiZero f50 Line.