Green, whose real name is Thomas DeCarlo Callaway, is expected to be arraigned Monday afternoon in a downtown Los Angeles courtroom once the charge is formally filed.
[Updated 12:26 p.m. PDT, Oct. 21: Green was formally charged Monday afternoon with furnishing a controlled substance to a 33-year-old woman while dining in a downtown L.A. restaurant in July 2012.]
The woman claimed she woke up to find herself naked in the 39-year-old singer's bed.
But after two rounds of investigations, prosecutors declined to file sex-related charges against Green, citing insufficient evidence. Green has previously denied any wrongdoing.
The Los Angeles County district attorney's office plans to file a drug charge against the singer, who is known to millions as a judge on NBC's "The Voice," according to multiple sources.