Who played Dexter's infant son Harrison through season 7?

Evan and Luke Kruntchev played Dexter’s infant son Harrison through season 7.

The Kruntchev twins share the role of Harrison Morgan, Dexter and Rita’s son. Using twins for a very young television character is common because production can alternate children while complying with limits on the amount of time young performers may work. They are credited as recurring performers in seasons 5 through 7.

Harrison first appears as a baby in season 4, when Rita is murdered by Arthur Mitchell, the Trinity Killer. Dexter later finds Harrison sitting in Rita’s blood, deliberately echoing Dexter’s own childhood trauma. That image becomes one of the defining emotional memories of the series.

Harrison’s casting changes after the original series. Jadon Wells plays him in season 8, while Jack Alcott plays the older Harrison in Dexter: New Blood. Brandon Michael Bass appears as a dream version, and various uncredited infant actors are used earlier. Those later performers should not be substituted for the Kruntchev twins when the question specifies through season 7.