Akairos (Q."He who lives besides the ocean-spray") was an elf of Alqualondë, one of the Falmari. He was the brother of Ainairos who fell in battle against the Noldor forces in the First Kinslaying at Alqualondë. His death prompted many of the Falmari, including his brother, to speak out against the Noldor.
In the Book of Lost tales this character appears unnamed.