Officers issued CCTV images of a man they wished to speak with after the incident in London Road, East Grinstead, on June 17.
Police said a 39-year-old man from Hammersmith, London, was arrested on suspicion of sexual assault and bailed with strict conditions, pending further enquiries.
Sussex Police issued an appeal on June 26, and made the arrest on June 29.
Officers would like to thank the public for their help and support to identify the man.
1. Man arrested on suspicion of sexual assault by touching in East Grinstead
Police have arrested a man on suspicion of sexual assault by touching following an appeal Photo: Google