Contostavlos, of St Albans, Hertfordshire, stood in the dock in a white shirt, black trousers and black trainers as the charge was read to him.
He was granted unconditional bail and will stand trial at Chelmsford Magistrates' Court on June 18.
The former N-Dubz singer finished in second place on reality show Celebrity Big Brother in January.
More top news
MK Dons have signed midfielder Nigel Reo-Coker on a deal until the end of the season.
The Government's announced £30 million is to be spent dualling the A421 between Milton Keynes and the M1.
A woman from Ampthill has been found guilty of theft and jailed for 16 months after taking money from her elderly father.