The 19-year-old moved to Molineux from boyhood club Swindon Town during last year's January transfer window, but has been limited to five appearances in the Checkatrade Trophy so far.
However, he will now be given the chance to gain some first-team experience at Walsall, where he will wear the number 18 shirt.
"I'm delighted to have got the deal done and to be here at Walsall. I trained here at the start of the month and the gaffer made me feel very comfortable. He explained what was expected of me and I liked the set-up," he told the club's official website.
"I've played in League One before with Swindon and I want to prove to people that I can do it at this level. I like to play wide left, I'm right footed and I like one-on-one situations. I try to create and score goals, and I'll work hard for the team.
"During my time here, I want to play as many games as I can and help the club move higher up the table. The team have done well recently and we want to finish the season strongly."
Manager Jon Whitney added: "Will is really high thought of at Wolves. He's quick, dynamic and he'll be a good addition to the squad.
"I noticed him when he played against us for Swindon a few years back when he came on and created a goal. He's a technical player and a very grounded lad who fits into our ethos. We're really pleased to get him on board."
Randall could make his debut for Walsall against Millwall on Wednesday.