Methods, systems, and media for language identification of a media content item based on comments are provided. In some embodiments, the method includes: obtaining a plurality of comments associated with a media content item; selecting a subset of the plurality of comments based on one or more criteria; assigning, for each comment in the subset of the plurality of comments, a vector of language probabilities, wherein each component of the vector is assigned a language probability that indicates the likelihood that the comment includes content in a language from a plurality of languages; combining the vector of language probabilities for each comment in the subset of the plurality of comments to generate a combined language vector; identifying a language associated with the media content item based on the combined language vector; and performing an action based on the identified language.