Prince Majed Abdulaziz Al-Saud is accused of trying to force a woman to perform a sex act on him, Los Angeles police Officer Drake Madison said.
Police were called to a home in the city on Wednesday afternoon, where they interviewed numerous people.
Al-Saud has been released on $300,000 bail and is set to appear in court on October 19.
"It's unclear whether Al-Saud has diplomatic immunity. CNN left a message at the Saudi Embassy in Washington but has as yet received no response.