The Blue singer is accused of hitting his fiancee, 26-year-old Samantha Millar, in the face while in a car in London on Wednesday (18.08.10).
A Metropolitan Police spokesman confirmed: "Lee Ryan, self-employed, of Henley-on-Thames, is due to appear on bail charged with common assault."
Samantha called police after the incident, and Lee was arrested at his home in south London after reportedly refusing requests to go for questioning.
The 27-year-old star - who has a nine-month-old son Rayn with Samantha - vehemently denies the charges.
His spokesperson said: "Lee 100 per cent denies common assault.
"He will be fighting theses charges in court".
The 'Army of Lovers' hitmaker is due to appear at the City of Westminster Magistrates' Court on August 27.
This is not the first time the singer has been in trouble with police.
He was arrested in December 2007 for assaulting a taxi driver.
He later appeared in court, where he was fined £300 and complained he "felt targeted because he is famous".
Last year, he was quizzed by police on suspicion of smoking cannabis.