Orr joined the Blues from Lowland League side BSC Glasgow last summer and was a key player in the side’s push for promotion.
He hit 11 goals in 31 appearances, including eight in the league.
However the 24-year-old – who has also had spells with East Stirlingshire, Livingston and Queen’s Park after coming through the ranks – has turned down a new deal in favour of a switch to another club.
Stranraer confirmed the news on their website, adding: “In addition to being top scorer this season, the striker was a popular member of our dressing room and we thank him for all his efforts in the Stranraer jersey.”
Also on his way from Stranraer is midfielder Ally Taylor who has returned to parent club Kilmarnock at the end of his loan spell.