Provided are a thermoplastic polymer capable of reducing a dielectric dissipation factor in high frequency bands and a film thereof. The thermoplastic liquid crystal polymer includes repeating units represented by the following formulae (I), (II), (III) and (IV), in which a molar ratio of a total amount of the repeating units represented by formulae (I) and (II) to a total amount of all the repeating units in the thermoplastic liquid crystal polymer is 50 to 90 mol %, and a molar ratio of the repeating unit represented by formula (III) to the repeating unit represented by formula (IV) is the former/the latter=23/77 to 77/23.