The country's Crown Prosecution Service says there is insufficient evidence to afford a "realistic prospect of conviction" and has ordered the police not to take any further action.
British media had reported that Bale's mother and sister told police he assaulted them at the hotel a day before he attended the European premiere of his film "The Dark Knight."
Bale denies the allegation.
The Sun tabloid reported last month that police waited a day to question Bale to allow the actor time to attend the premiere of the film in London's Leicester Square. Bale was questioned for several hours at a police station before being released on bail.
Prosecutors said the decision not to pursue the case was based in part on the feelings of Bale's mother and sister.
Wales-born Bale first made a splash as the child star of Steven Spielberg's "Empire of the Sun" in 1987. His screen credits also include "American Psycho," "The Machinist" and "Batman Begins."
In "The Dark Knight," the 34-year-old Bale reprises the role of wealthy playboy Bruce Wayne and his crime-fighting alter-ego Batman, a brooding vigilante superhero still scarred by the murder of his parents.
Ever since its debut four weeks ago, "Batman - The Dark Knight" has ruled the box office roost.
It's already the third-highest grossing movie ever, behind "Star Wars" and "Titanic."