From the way that Barliman Butterbur reported his death, it seems unavoidable that Mat Heathertoes must have been one of the Big Folk (and indeed, Heathertoes is specifically given as a family name used among Men). It is slightly odd, then, that the names Mat and Heathertoes are also separately discussed as names used by Hobbits, rather than by Men. (In Appendix F to The Lord of the Rings, Mat is an abbreviation of the Hobbit-name Matta, and in Tolkien's guide for translators he explains Heathertoes as a name given by Men to Hobbits.) Since Mat Heathertoes' identity as a Man is not realistically in question, it seems that both of these names must have been shared in Bree by the Big Folk and the Little Folk alike.

When Barliman Butterbur listed the names of those killed in the fighting at Bree, for three of the victims he explains where in the Bree-land, outside of Bree itself, they had lived. For Mat Heathertoes (and another Man, Rowlie Appledore), he merely gives their names, but doesn't place them elsewhere in the Bree-land. Though hardly conclusive, this would seem to imply that the two Men were from the village of Bree itself.

In Appendix F II to The Lord of the Rings, Mat is given as a 'real' (that is, untranslated) Hobbit-name, representing a shortening of Matta (or earlier Mattalic in the drafts from volume XII of the The History of Middle-earth). Though described as a Hobbit-name in those sources, given that Mat Heathertoes seems to have been a Man, we would have to assume that Mat was actually a more general Westron name used by Hobbits and Men alike.