Lil Nas X was just booked for obstructing an officer — following his late-night escapade that ended with him stark naked and tussling with police officers!!!

TMZ Hip Hop can confirm the “Old Town Road” rapper is currently in custody for the misdemeanor offense at the Van Nuys jail just outside Los Angeles. Nas is currently being held without bail.

We broke the story … Lil Nas X was spotted by a bystander early this morning wearing nothing but tighty whities and cowboy boot while parading down the middle of a street.

Law enforcement sources say he eventually stripped down naked and lunged at an officer. Our cop sources tell us witnesses called police and Nas was rushed to a hospital after it was reported he suffered a possible drug overdose.