Wes, who has started each of the Saddlers' last thirteen games, has played a crucial role in the team's recent return to form which has resulted in the team rising into the top half of the League Two table.
Scoring five goals from a total of twenty-four first-team appearances, 22-year-old Wes had unsurprisingly begun to attract the interest of other clubs keen to add him to their ranks.
But, after penning his new deal, McDonald - a former Birmingham City prospect - admitted he is delighted at extending his time in the Black Country and is ready to kick on in the second half of the campaign.
Speaking via the club's official website, Wes said; "I’m delighted to get the deal done. I feel at home here like I’ve said in the past and I’m very grateful for the club for putting their trust in me and I’m really happy to get it sorted, It’s about cracking on now that I have signed my deal.
"I am very happy that it is all sorted and that everything is done. I just want to get back out there on the pitch and continue pushing up the table and keep helping the team.
"I’ve been working really hard since I joined the club and I’m trying to add numbers to my game. Every time I’m on the pitch I’m always trying to help the team out whether that be creating a chance for my teammates or scoring a goal and I just want to continue doing that.
"I’ve said it before, the fans are brilliant with me and with the team, they’re always getting behind us. I just want to keep showing them what I can do and I want to continue helping the team push on."