Tyrannomimus (meaning "tyrant mimic") is an extinct genus of ornithomimosaurian theropod dinosaurs from the Kitadani Formation of Japan.

The generic name, "Tyrannomimus", is a reference to its morphological similarities with tyrannosauroids, particularly the vertical ridge of the ilium previously believed to be a synapomorphy of that clade and shared with Aviatyrannis.

[1] Tyrannomimus was entered in a phylogenetic analysis by Hattori et al. (2023) and placed within the family Deinocheiridae, as the sister taxon to Harpymimus.

[1] Tyrannomimus lived alongside a diverse assemblage of animals, most of which are named after Fukui Prefecture.

These include the sauropod Fukuititan, the ornithopods Fukuisaurus and Koshisaurus, and the theropods Fukuiraptor, Fukuivenator, and Fukuipteryx.