Aguilera, 33, and Rutler, 29, a film producer, are set to welcome their first child together, PEOPLE confirms.
The couple met on the set of Burlesque, the 2010 film they both worked on.
"They're very much in love and are really excited to take this next step!" a source close to the pair tells PEOPLE.
The Voice coach is already mom to Max Liron, 6, her son with ex-husband Jordan Bratman.