Michael Sinden, 34, has been charged with sexual assault by penetration on a woman known to him.
This is alleged to have occurred in Eastbourne on 10 March 2022.
Sinden, a Sussex Police Inspector, is suspended from duty. The alleged offence happened off duty.
He will appear at Brighton Magistrates’ Court on Wednesday 25 January.
The matter was referred to the Independent Office of Police Conduct who directed that a local investigation by the Professional Standards Department should be conducted.