The fourth season of the Canadian police drama Rookie Blue starring Missy Peregrym, Ben Bass and Gregory Smith premiered on May 23, 2013 on Global in Canada.

Adam MacDonald and Eric Johnson continued to recur, whilst Aliyah O'Brien joined the guest cast as Holly Stewart.

Andy has to learn to work with a new partner, Officer Marlo Cruz, who also happens to be Sam's new girlfriend.

Meanwhile, Dov discovers his one night stand is actually a fellow police officer—a new transfer and Frank's goddaughter, Chloe Price—who he ends up working with when 15 Division has to deal with chasing down a burglar with a unique MO.

The following is a table for the United States ratings, based on average total estimated viewers per episode, of Rookie Blue on ABC.