Yokoi Yayū (横井 也有, October 24, 1702 – July 15, 1783) was a Japanese samurai best known for his haibun, a scholar of Kokugaku, and haikai poet.

Yayū was born in Nagoya, the first son of Yokoi Tokihira (時衡) who served the Owari Domain.

He inherited the Yokoi House's patrimony at twenty-six and held important posts of the Owari Domain.

Yayū also excelled in Japanese martial arts, studied Confucianism and learned haikai from Mutō Hajaku (武藤巴雀) and Ōta Hajō (太田巴静).

Mori Senzō (森銑三), a student of old Japanese literature, compared his hokku to senryū, and said they were not as interesting as his haibun.