Aasu is a village in Haljala Parish, Lääne-Viru County, in northeastern Estonia.
Aasu was attested in historical sources as ÃÂ÷þúÃÂûà(Azokjulja; i.e. 'Azo village') circa 1900. The name Aasu is derived from the common noun aasu, referring to a bend in a river or a meadow in such a bend.