Jeremy.
Jeremy is the boyfriend of Sarah's mother Linda Williams.
The character only appears in photos in the film, and is portrayed by David Bowie. Bowie also appeared in the film as Jareth, the film's primary antagonist.
Jeremy is referenced in the film's novelization and its manga sequel, Return to Labyrinth.
Role In The Film
Jeremy only appears in photos alongside Linda in the film, and goes unnamed. The headlines under the photos he appears in imply a romance between him and Linda, and suggest that both are actors in the theatre.
Appearances In Other Media
Novelization
Most of the information about Jeremy is found in the film's novelization. In the novelization he is said to be a handsome and sophisticated actor. His friendly, easy-going personality endears him to Sarah, and she clearly enjoys spending time with him and her mother. Jeremy and Linda are shown to live an exciting, fast paced life consisting of premieres, theatre performances and dinner dates at exclusive resturants. Sarah is shown to model some of her affectations on Jeremy's, considering her step-mother's behaviour to be 'hammy' as a result of a comment Jeremy made to her about a fellow actor. He owns a vintage black mercedes, speaks French and is a member of an exclusive club, all attributes that deeply impress Sarah.
Return To Labyrinth
In the fourth volume of this manga sequel to the film, Jeremy appears as a puppet in a puppet show put on by Jareth to stir Sarah's memories of her time in the Labyrinth. In the scene, Linda is shown to abandon Sarah in order to be with Jeremy.