Striker MacLean has signed a two-year extension, while winger Croft has penned a one-year deal.
The news is a major boost for St Johnstone as they prepare for the Scottish Cup final later this month.
MacLean and Croft have established himself as key performers for St Johnsone and Saints boss Tommy Wright was delighted to keep hold of the pair.
"It's great news for the club and the players and a nice boost ahead of cup final week," Wright told the club's official website.
"Both players have done well for us and I am delighted to have them tied up."