As exclusively revealed in yesterday's SportTimes the 31-year-old has penned a one-year deal.
The former Chelsea kid's arrival will help make up for the departure of Dutch striker Nigel Hassel-baink, who ironically has signed with the Perth Saints.
Lennon revealed: "We have known for some time exactly where we want to strengthen our squad in order to continue our journey.
"We have a tight budget and a small squad compared with many of our rivals in the SPL, so every player in that squad has a vital role.
"That's another piece of the jigsaw in place and represents a great piece of business for the club. I am delighted to have Sam on board and wish him every success in his Saints career."
Parkin's arrival means Saints now have four strikers in their squad with Stevie Thompson, Dougie Imrie and another recent recruit, Lewis Guy, from MK Dons.
The powerful striker will give Lennon the option to rest Thommo who made 43 appearances last season.
It will also give Lennon the option of going for a more physical approach up top by playing both men in tandem.
The Saints boss said: "We have had our eye on Sam for a while and know exactly the qualities he will bring.
"He will add a presence in the box for us and provide us with options in the front line. Not only does he have an eye for goal, but he links play very well."