Andrews spent the second half of last season at The Hawthorns, scoring twice in 14 appearances, but was a free agent again this summer.
The Republic of Ireland international has now sealed a move to the Reebok Stadium, and Bolton manager Owen Coyle is delighted to have won the chase for his signature.
Coyle believes the experience of Andrews, who has also played for clubs such as Wolves, Milton Keynes Dons and Blackburn, will be a valuable asset as Bolton strive to win promotion back to the Premier League.
"We are pleased to have been able to bring in Keith early in the transfer window as there were a number of clubs interested in signing him," Coyle told the club's official website.
"He is highly experienced both in domestic and international football, and he will bring strength, competition and a goalscoring threat to our midfield."
Bayern Munich are kings of Germany and hope to be crowned kings of Europe at Wembley later this month!
Chelsea won the Europa League on Wednesday. The Blues defeated Benfica 2-1 on injury time goal from Ivanovic.
The Juventus jersey for the 2013/14 was released earlier this week. Be the first to wear the colors of the Old Lady.
Ajax has released their away soccer jersey for the 2013/14 season. Get in the Gear.
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 Liverpool 2013/14 soccer jersey is available for pre-order. The Reds are eager to compete for silver next season.
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.
One of the top soccer cleats for control the Nike CTR360 will not let you down on the field in tight spaces.
Borussia Dortmund hears Wembley Calling and are headed to London for the Champions League final.
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.