St Johnstone beat Raith Rovers 2-0 at McDiarmid Park on Friday night before receiving the William Hill Championship trophy.
Simo Valakari's men were crowned champions on Tuesday when they won 2-0 away to Dunfermline Athletic and they were also too strong for Rovers.
Jamie Gullan opened the scoring from the penalty spot midway through the first half and it was Gullan who sealed the points with a superb free-kick shortly before half-time.
Saints can now look forward to top-flight football again next season while the result means Dougie Imrie's men can't make the play-offs and Dunfermline are assured of a top-four finish.