"I'm delighted. Everyone knows that I am happy at Walsall and to have my future sorted out is a big relief to me," he told the club's website.
"I've got a young family, my daughter Grace is just 10 months old, so it was important to get things in order."
Saddlers manager Chris Hutchings said: "I'm pleased to have Alex on board. He is an important member of the squad and, like last season, I expect to see him competing for a regular place in the starting line-up.
"It is important that the club continues to progress and look to the future and now, with Alex's long-term future secured, he too can concentrate on his ongoing development."
Source: BBC Sport
Source: BBC Sport