The 35-year-old Irishman has joined the Saddlers on a one-year deal following his release from Ipswich.
He comes in having played 171 times in the Premier League across his spells with both Wolves and Burnley, while also gaining 50 Ireland caps.
Excited Walsall boss Matt Taylor said: “Stephen is someone who I have played with and has huge experience in the game.
“He’s a player that’s played at the top. We’re extremely happy to have someone of Stephen’s quality joining the club.
“The biggest thing for him is he wants to be part of the journey that we’re on at this football club so from my perspective, I’ve always spoken about good people first, followed by a good player and Stephen fits the mould.
“It will be great for other players in the group to learn from him because he’s a fantastic professional and somebody that’s got huge experience domestically and internationally but more importantly, he still wants to be successful and we hope he can help us to do that here.”
Ward helped Wolves clinch the Championship title in 2009 before playing with Taylor at Burnley.
He also played at both Euro 2012 and Euro 2016 for Ireland.
Last season, Ward made 29 starts in League One for Ipswich. He has had spells with Stoke, Brighton and Irish club Bohemians over his career as well.
“It's exciting. I have been in with the lads training for a couple of days now, having a look at the place, and I am really impressed with how the head coach is trying to go about his business and his ambition for the season," added Ward.
"I have been really impressed from speaking to the head coach and I am really excited to get going this year.”