Dossier 51 is a 1978 French crime drama film directed by Michel Deville and based on a novel by Gilles Perrault. Deville and Perrault won a César Award for Best Writing for their adaptation. The film was screened in the Un Certain Regard section at the 1978 Cannes Film Festival.


An elaborate surveillance operation is mounted by a French intelligence agency on a French diplomat, codenamed 51. While his professional life is not suspect, clandestine investigations into his private life reveal an increasing number of vulnerabilities.