The musician, whose legal name is Montero Lamar Hill, pleaded not guilty on Monday in a court appearance to three counts of battery with injury on a police officer and one count of resisting an executive officer, the district attorney's office said.
The charges were far more serious than initial reports that he was being investigated for a misdemeanour, and, with convictions, the counts could collectively bring a sentence of more than 10 years in prison for the singer and rapper whose Old Town Road was one of the biggest hit singles in history.
Police said officers found the 26-year-old walking naked on Ventura Boulevard, a major thoroughfare in the Studio City neighbourhood, shortly before 6am on Friday.
They allege he charged at the officers when confronted and was arrested. Police, suspecting a possible overdose, took him to a hospital where he spent several hours before being taken to jail, where he has remained since.
He was being held on $US75,000 ($A115,600) bail, conditional on attending drug treatment. It's not immediately clear whether he had posted it and been released yet. A message to his lawyer, Christy O'Connor, was not immediately answered.
But O'Connor told a judge Lil Nas X has led a "remarkable" life that has included winning two Grammy awards.
"Assuming the allegations here are true, this is an absolute aberration in this person's life," O'Connor said in court, according to NBC.
"Nothing like this has ever happened to him."
The charges were first reported by TMZ.
Hill is set to return to court on September15 for his next pre-trial hearing.
The rapper and singer from Atlanta is best known for 2018's country and hip-hop merging Old Town Road, which spent a record 19 weeks at No.1 on the Billboard Hot 100 and won him his Grammys.
Known for his genre-bending, innovating sounds and style, his first full studio album, 2021's Montero, went to No.2 on the Billboard album chart and was nominated for a Grammy for album of the year.
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