Essex Police said the alleged attack happened outside a nightclub in Chelmsford in the early hours of Thursday morning.
The 26-year-old, whose real name is Costadinos Contostavlos, has been bailed pending a court appearance.
Dappy was arrested after an appearance at Chicago's nightclub in the city.
He posted a message on Twitter which read: " Had a great night in Chicagos. Crowd was amazing."
An Essex Police spokesman said: "Costadinos Contostavlos , aged 26, from Sandridge, St Albans, has been charged with an assault by beating following an incident outside a nightclub in Moulsham Street in Chelmsford in the early hours of February 27.
"He has been released on bail prior to his appearance at Chelmsford Magistrates' Court on March 19."
Dappy finished in second place on reality show Celebrity Big Brother last month.