Proto-Austroasiatic is the reconstructed ancestor of the Austroasiatic languages. Proto-Mon-Khmer (i.e., all Austroasiatic branches except for Munda) has been reconstructed in Harry L. Shorto's Mon-Khmer Comparative Dictionary, while a new Proto-Austroasiatic reconstruction is currently being undertaken by Paul Sidwell.

Scholars generally date the ancestral