This category includes the native flora of Northwestern Mexico, in North America. Taxa of the lowest rank are always included. Higher taxa are included only if endemic.

For the purposes of this category, "Northwestern Mexico" is defined in accordance with the World Geographical Scheme for Recording Plant Distributions, with Mexico as level 2 region #79, and Northwestern Mexico as level 3 MXN.^[1] This area is defined by the political boundaries of these four states: Baja California, Baja California Sur, Sinaloa, and Sonora.