Stefan Kostadinov Valdobrev (Bulgarian: Стефан Костадинов Вълдобрев; born 20 May 1970) is a Bulgarian actor, film/theatre composer, singer-songwriter and filmmaker. He received classical training at the National Academy of Theatre and Film Arts in Sofia.

Valdobrev rose to prominence in the early 1990s, mainly with his hit songs, which made him extremely popular and gained him idol status on the Bulgarian music scene, twice being awarded as best male artist at the National Music Television ceremonies. Despite that he never quit his acting career and took part in numerous performances which have spanned a wide variety of genres from classical to contemporary drama, and from popular comedies to alternative, non-commercial projects, all staged by the most prominent Bulgarian directors on the most significant theatre stages. At that time Valdobrev gradually entered the world of film and theatre music and since 1992 has gone on to enjoy composing the original scores for more than 70 stage performances and 20 feature and documentary movies, winning many plaudits and awards for his work. In 2000 he received the Golden Rose film award for debut for the Dog's Home original movie soundtrack featuring Arabel Karajan. In 2008 he composed the music for Stefan Komandarev's highly acclaimed film The World is Big and Salvation Lurks Around the Corner, a Bulgarian-German co-production with Miki Manojlovic in the lead role, which won a considerable number of international awards and reached the Short List of The Academy Awards 2010 for Foreign Language film.

Although Valdobrev continued performing in theatre (Shakespeare's Much Ado About Nothing, Dostoyevsky's The Brothers Karamazov, Bulgakov's The Master and Margarita, Muller's Hamletmachine, Anouilh's Eurydice), he gradually moved away from this area, and also from the music stage, to become more established as a film actor. In 2004 he got his break in Burning out, for which he received the Golden Rose for Best Male performance at the National Film Awards.

In 2006-2007 Valdobrev completed a film directing specialization at the Academy of Performing Arts in Prague (FAMU). After graduating from there he directed a few short films, TV programs and music videos. He made his director's film debut in 2010 with the documentary comedy drama My Mate Manchester United. Provided with the cameo appearance of the Bulgarian football superstar Dimitar Berbatov, the film won two international awards and was presented in the competition of the official selection of 21 major world film festivals: IDFA Amsterdam, HotDocs Toronto, ZagrebDox, Sarajevo and Warsaw among them.

After being away from the rock stage for almost a decade in 2012 Stefan Valdobrev decided to rejoin his old band "The Usual Suspects" and to start recording songs and performing live in concerts again.