Thomas's giant deer mouse

{{Short description|Species of rodent}}

{{speciesbox

| name = Thomas's giant deer mouse

| status = EN | status_system = IUCN3.1

| status_ref = {{cite iucn |author=Álvarez-Castañeda, S.T. |author2=Castro-Arellano, I. |date=2019 |title=Megadontomys thomasi |volume=2019 |page=e.T12942A22353461 |doi=10.2305/IUCN.UK.2019-2.RLTS.T12942A22353461.en |access-date=13 November 2021}}

| genus = Megadontomys

| species = thomasi

| authority = (Merriam, 1898)

| synonyms =

}}

Thomas's giant deer mouse (Megadontomys thomasi) is a species of rodent in the family Cricetidae.

It is found only in Mexico.