Tom Clancy's Jack Ryan will return for a fourth and final season next month. Amazon announced in a press release yesterday that Season 4 of the political action thriller series will premiere June 30. Jack Ryan is based on the character created by author Tom Clancy. The series follows Jack Ryan (John Krasinski), a Marine veteran and financial analyst working for the Central Intelligence Agency (CIA). Season 4 will see Ryan take on "his most dangerous mission yet: facing an enemy both foreign and domestic."