Riley has arrived at Bescot on a two-year deal after turning down fresh terms at League Two rivals Carlisle.
The versatile ex-Manchester United man can play either as a wing-back or in central midfield.
When asked what attracted him to Walsall, Riley told the club: “Definitely the ambition of the club.
“I’ve played against Walsall a few times over the last two years and I’ve always thought that they’ve played good football.
“You know they do want to get out of the league and strive to get into League One and push for the Championship.
“I’m an ambitious football player and want to get to the highest level possible.
“Hearing the ambition from the manager and things like that, that’s what drove me to come to this club.”
Meanwhile, Michael Flynn will start getting his new-look Walsall group in tip-top shape as they report back for pre-season training next week.
The Saddlers – in the wake of the Trivela Group takeover and several players being signed – will return to their Essington base on Thursday, June 23.
Walsall will be put through their paces ready for the first pre-season friendly against Villa on Saturday, July 9 at Bescot.
All five of their confirmed fixtures are in the Midlands, with trips to Telford, Leamington, Solihull Moors and a home clash with Coventry being the other warm-up games.
The Saddlers are not thought to be going away on a training camp and will stay local before the start of the new League Two season on Saturday, July 30.
Walsall will find out their opening-day opponents when the EFL fixtures are released, also on Thursday.