You is an American psychological thriller television series. It is developed by Greg Berlanti and Sera Gamble. The first season is based on the 2014 book "You" by Caroline Kepnes. The series stars Penn Badgley, Elizabeth Lail, Ambyr Childers, Victoria Pedretti, James Scully, Luca Padovan, Zach Cherry, Shay Mitchell, Jenna Ortega and Carmela Zumbado. The series first appeared on Lifetime. The series has been made by Netflix since the second season.