Millipede diversity in tropical regions, and in Mexico in particular, is still mostly unknown. A modest but recurrent source of new Mexican species is the colonization of exotic species, due to human activity. The invasive species Cylindrodesmus hirsutus Pocock, 1889 has spread from its area of origin in Indonesia or Melanesia and become a virtually pantropical species. Although long known from South and Central America, reports from the Caribbean are sparse and limited to some eastern islands and southern Central America. On 9 March 2016, two adult specimens were found on Cozumel Island, Quintana Roo, in an area of medium semideciduous tropical forest. This paper comprises the first record of this species from Mexico and the northern Caribbean. Given the intense commercial activity in the region, the presence of more populations both in Cozumel Island and in the mainland coast is highly probable.