Nipsey Hussle spent the night in jail simply because he left his ride in a disabled parking spot -- well, that and his outstanding warrants ... TMZ has learned.

LAPD busted the rapper around 9 PM Monday when officers spotted his car illegally parked -- Nipsey doesn't have a disabled placard -- and when they ran the plates, discovered he had warrants for previous traffic violations.

Nipsey clearly ain't sweating the arrest. He was back in the studio at 5 AM Tuesday after bailing out on "some bulls**t" ... as he put it.

Park at your own risk, Nipsey. Or try Lyft.