Hmong is the language of the Hmong ethnic group, who live in mountainous regions from southern China, through Vietnam and Laos to Thailand. The two main dialects are White Hmong (Hmong Daw) and Green Mong (Mong Njua).
Dr. Jacques Lemoine (2005), in a paper that provided much of the data for this map, estimated the total population of Hmong speakers to be between 4 and 5 million, in 10 territories; the largest number (roughly 2.8 million) are in southern China, the remainder are found, in order of descending size, in Viet Nam, Lao People's Dem. Republic, the United States, Thailand, France, Myanmar, Australia, Argentina and Canada.
Reference: Lemoine, J. (2005). What is the actual number of the (H)mong in the world?. Hmong Studies Journal, 6.