The couple reportedly got engaged in Sun Valley, Idaho, during the Christmas holiday.
The news was confirmed by Barrymore’s rep to People, along with a picture of the couple.
“He’s madly in love and knows she’s The One,” a friend of Kopelman told Us Weekly.
Barrymore, 36, has been dating Kopelman, 34, who is the son of Chanel’s former chief executive, Arie Kopelman, for at least a year.
This wouldn’t be the first marriage for Drew. She was previously married to club owner Jeremy Thomas in 1994 and comedian Tom Green in 1999.