The 25-year-old Northern Ireland international, who left the Gers at the end of last season, will pen a two-year contract with the League One club.
"Andy has a fantastic goal record in Scotland and he can handle playing for a big club, as he has shown with Rangers," boss Simon Grayson told the club's official website.
"He is also an international player. He is a good age and has some good qualities that we are looking for in the squad."
Little has spent the past eight years at Rangers after coming through the club's youth academy.