"The pull of Hibernian was too much for me," said Swanson.
"It's always been an ambition of mine to play for the club and I am looking forward to this new challenge and to help achieve their goals back in the Premiership."
"So, it goes without saying, my decision to leave McDiarmid Park was not taken lightly.
"I want to thank the manager, Tommy Wright, who has supported me in so many ways, on and off the field. His trust in me on the football park allowed me to flourish. The way he treated me like an adult off the park also helped me to mature and develop as a person.
"Now that we are in the top six yet again, which is yet another fine achievement, for the next five games it's my focus to make sure I play my part in helping St Johnstone qualify for a European place."
At least he never called them a bigger club...