Naoyuki Uchida (内田 直行, Uchida Naoyuki, born December 23, 1960), who writes under his pen name Yukito Ayatsuji (綾辻 行人, Ayatsuji Yukito), is a Japanese writer of mystery and horror. He is one of the founders of Honkaku Mystery Writers Club of Japan and one of the representative writers of the new traditionalist movement in Japanese mystery writing. His wife is Fuyumi Ono, a Japanese fantasy and horror writer who is known for her fantasy series The Twelve Kingdoms.

His first novel The Decagon House Murders was ranked as the No. 8 novel on the Top 100 Japanese Mystery Novels of All Time.

In 2018, a minor planet (2001 RG46) was named as Yukito Ayatsuji.