Logan Paul just went scorched-earth on Jimmy Kimmel for dissing him last week ... saying the late-night host is "so f***ing lame" for making him the butt of a joke.

In case you missed it, Kimmel name-dropped the YouTube superstar during one of his opening monologues ... when he made a reference to former President Donald Trump's wildly expensive appearance at Triller Fight Club.

"Between Logan Paul and Donald Trump, boxing is once again the top source of income for the very worst people," Kimmel joked.

But, LP ain't laughing ... in fact, he's calling out the host for bashing him after he was a guest on the same show just 3 years ago.

"F*** you, Jimmy Kimmel. F*** you," Logan said on his "Impaulsive" podcast Tuesday.

Paul has received similar treatment recently -- he was mentioned in Bo Burnham's song, "That Funny Feeling," during his popular Netflix special, "Inside" ... which LP says he was cool with.

Paul also takes aim at Kimmel's staff ... saying, "Your writers are so lacking content and creativity they had to do some lame-ass Paul joke??"