Davidson made more than 160 appearances for Preston
Scotland full-back Callum Davidson is returning to St Johnstone after signing a one-year deal with the Perth club.
The 34-year-old, capped 17 times, left the Saints to join Blackburn Rovers in a £1.75m deal in 1998.
He moved to Leicester in 2000 and has just been released by Preston, having joined the Deepdale club in 2004.
Davidson signed a contract extension at Preston in 2007, then a further three-year deal in the summer of 2008.
The Preston captain made 20 appearances in his final season at the club, scoring three goals.