After developing an interest in filmmaking, Lannoo enrolled at the Institut des Arts de Diffusion in Brussels and graduated from there in 1995.
His first short film, I Love the Movies (1998), was screened at the 1999 Brussels Film Festival, where it won both the Crystal Star for Best European Short and the Golden Iris for Lannoo.
[1] Lannoo made his feature-length debut in 2001 with Strass, an experimental film in which elements of reality and fiction are mixed together at a drama school.
Upon release, the film was met with general acclaim from critics, although its religious references and depiction of violence sparked controversy.
[4] At the 4th Magritte Awards, In the Name of the Son received seven nominations, including Best Film and Best Director for Lannoo.