Secret Diary of a Call Girl follows Hannah Baxter (Billie Piper), an independent and witty London graduate who secretly works as a high-class escort. Using the name of "Belle," she's always loved the single life, claiming she doesn’t need relationships because she gets what she needs from her work. Other actors in the series include Iddo Goldberg, Joanna Bobin, Cherie Lunghi, Callum Blue, James D’Arcy, Ashley Madekwe, Nadia Cameron-Blakey, Ace Bhatti, Toyah Willcox, and Stuart Organ.
The series is produced in the UK and debuted there on ITV2 back in 2007. Showtime considered producing an American version of the series but ultimately decided to purchase and air the UK series instead.