President Donald Trump ain’t happy that ABC put Jimmy Kimmel back on air … and let everyone know by ripping into the “fake news” network Tuesday night.

Check out his post on Truth Social — he says he “can’t believe” Jimmy’s suspension was lifted, theorizing … “Something happened between then and now because his audience is GONE, and his ‘talent’ was never there.”

The prez goes on to question why ABC would want someone “who does so poorly, who’s not funny, and who puts the Network in jeopardy by playing 99% positive Democrat GARBAGE” back on air.

DT then threatens to sue ABC and wraps up his rant by calling them “a true bunch of losers.”

Trump certainly minced no words … and we’ll have to stay tuned regarding his alleged upcoming legal action against ABC.

As you know, “Jimmy Kimmel Live!” returned to air Tuesday evening … and Jimmy made a jab at 47 for wanting to see his fellow Americans crash and burn because he “can’t take a joke.”

He urged viewers … “We have to speak out against this bully. He’s not stopping. And it’s not just comedy. He’s gunning for our journalists, too. He’s suing them, he’s bullying them.”

JK also clarified his comments about Charlie Kirk‘s murder that got him yanked from air, and shared a heartfelt message of solidarity.