Fox entertainment president Kevin Reilly recently revealed that the sci-fi drama is losing money for Fox on Friday nights.
"My gut says that the head of Fox doesn't go on national television and say 'I'm not in the business of losing money' as a joke," Jackson told the MTV Movies Blog.
Jackson added that, if Fox declines to pick up a fifth season, Fringe could be revived by a cable network.
"I think there's a possibility that if people just watched the show on the day and date, and if the numbers came back, [renewal] is a possibility [on Fox]," he said. "[But] they've talked about maybe going off network with it, too.
"The TV landscape is a different place than it used to be, so [cancellation on Fox] might not be death."
Jackson recently insisted that Fringe deserves a real ending, calling on Fox to give the show's writing team enough time to reach a suitable conclusion.
"The most important thing to me about Fringe is that it finishes properly," he said. "You can't bring people along a journey like that for all those years and then just cut it off. It sucks."
Fringe continues on Fridays at 9/8c on Fox. The show returns to Sky1 in the UK in February.
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Watch a preview for the next episode of Fringe below: