The Cleveland Show hasn't been officially cancelled, but with the long lead time needed for animated series, FOX has yet to order additional episodes, which isn't a good sign for Seth MacFarlane's Family Guy spinoff.
FOX has already renewed The Simpsons, Bob's Burgers, Family Guy and American Dad and has the new animated series Murder Police on the way. As of right now, new Cleveland episodes will run through May, as Season 4 wraps up.
As The Wrap points out, FOX has been known to pull its animated series from the schedule, only to bring them back at a later date (à la Family Guy and King of the Hill). However, TVLine was also reporting Cleveland's alleged cancellation earlier this week.
Again, there's been no official word on the show's cancellation, but for now it's likely that The Cleveland Show has run its course.
“The most terrifying fact about the universe is not that it is hostile, but that it is indifferent. If we can come to terms with this indifference and accept the challenges of life within the boundaries of death, our existence as a species can have genuine meaning and fulfillment. However vast the darkness, we must supply our own light.” - Stanley Kubrick