PC Muhammed Miah has been charged after a woman reported being touched inappropriately by a man in January 2020.
Miah, who was based at the Central East Basic Command Unit, was off-duty at the time the alleged offence happened.
He was charged with one count of sexual assault by touching on January 5.
He has been suspended from duty, the Met Police confirmed on Thursday.
He is due to appear at Highbury Corner Magistrates' Court on February 2.