This thesis addresses the issue of language use, in particular sociolects and their representation in contemporary French cinema. Cinema is one of the most influential forms of mass media and because of that, it has an important role in the transmission of social, cultural and political ideas as well as the representation of different social and language communities. Language is not a unified concept in society, but consists of many variations, like sociolects, which represent the typical speech of a certain social group. In this research we used a corpus of eight films from the period 2000-2017: four mainstream and four award-winning films. The study focussed on which sociolects were present in the films, in what way, and what effect the character's language use had on viewers' perception of them. Commercial films have shown that because of their accessibility to the wider public, they use a much more standard language, which means that any deviations are mainly used for style and effect. The standard language, therefore, both in films and in real life represents a neutral, inconspicuous form of speech. On the other hand, the occasional use of non-standard language in popular films means a deviation from the neutral state, whereas in the art films the variations are more frequent and nuanced. Films containing non-standard sociolects are less popular amongst wider audiences, which is an expression of linguistic social ideology that favours the use of normative, standard language in the media. The lack of representation of other sociolects consequently means that they do not get the opportunity to reassess their value and continue to bear a social stigma. The speech in the films therefore shows a fictional state and not the actual real use, but it is nevertheless an important indicator of the current language ideologies in society as well as the hierarchy of sociolects.