McKenna returned to television in 2015, when she teamed up with singer and Comedian Rachel Bloom to create the romantic musical comedy-drama Crazy Ex-Girlfriend. The show was originally developed for Showtime, with a half hour pilot produced. When Showtime opted not to proceed, McKenna and Bloom reworked the series for The CW, including expanding it into an hour-long format. The CW renewed the series for a second season, which premiered on October 21, 2016, and a third season, which premiered on October 13, 2017. McKenna is the series' showrunner and an executive Producer.