The Magdalena rat (Xenomys nelsoni) is a species of rodent in the family Cricetidae which is found only in a small region of western Mexico.

The common name comes from the village where the first specimen was collected, and the second part of the scientific name refers to the collector.

The general body colour is cinnamon to yellowish brown, being paler on the head and fading to creamy white on the underparts.

[3] The species is endemic to Colima and southwest Jalisco, along the Pacific coast of Mexico.

[3] An endangered species, it is threatened by habitat destruction and fragmentation due to deforestation and development.