Northern Ireland Under-21 international McClean will join up with the Danske Bank Irish Premiership leaders to get more first-team opportunities.
McClean, 20, has made only two appearances in the Irn Bru Cup earlier this season and St Johnstone boss Tommy Wright feels the move will benefit his development.
"He'll have to fight hard for his place in a side which is doing very well this season," Wright said on the club website.
"The league is a good standard and it has really improved in recent years.
"It's a great opportunity for Kyle to get some game time and experience regular first-team football."