Hà Âi (; died 817; ) was the eighth king of Balhae. He was the son of King Kang, and the younger brother of King Chà Âng. He actively cultivated relations with Tang China, and imported many aspects of Tang culture and governmental systems, and sent Buddhist statues to Tang in 814. He married and had a son named Tae Yà Ânjun (). The king used chujak () as his Korean era name.