Reo-Coker, a free agent after leaving Bolton in the summer, has agreed a short-term contract until January.
"Ipswich is a sleeping giant in the Championship," the 28-year-old midfielder told the club's official website.
"It's a massive club with a great history and tradition. The facilities are first class and there is a terrific fan base. It's the right club at the right time for me and everything has just fallen into place.
"I had a good conversation with the manager (Paul Jewell). He's highly respected in the game for what he has achieved and I know what he's trying to do at the club.
"Ipswich may be at the wrong end of the table at the moment but it's still early in the season and I'm sure with the manager and players the club have, it's only a matter of time before things turn around."
Ipswich are currently second from bottom in the Championship with seven points from 10 games. Reo-Coker could make his debut at Hull next Saturday.
The adidas Nitrocharge is the most talked about new cleat in years. It was released on May 15 and will take your pitch by storm.
The Liverpool 2013/14 soccer jersey is available for pre-order. The Reds are eager to compete for silver next season.
The Juventus jersey for the 2013/14 was released earlier this week. Be the first to wear the colors of the Old Lady.
Borussia Dortmund hears Wembley Calling and are headed to London for the Champions League final.
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.
Bayern Munich are kings of Germany and hope to be crowned kings of Europe at Wembley later this month!
adidas has added some color to the Predator line with this new colorway. Released on May 17. Be the first to own a pair.
Ajax has released their away soccer jersey for the 2013/14 season. Get in the Gear.
Chelsea won the Europa League on Wednesday. The Blues defeated Benfica 2-1 on injury time goal from Ivanovic.