Fujiwara no Umakai (藤原 宇合, 694 – September 7, 737) was a Japanese statesman, courtier, general and politician during the Nara period.

[1] The third son of Fujiwara no Fuhito, he founded the Shikike ("Ceremonials") branch of the Fujiwara clan.

In the Imperial court, Umakai was the chief of protocol (Shikibu-kyō).

[1] Umakai had three brothers: Muchimaro, Fusasaki, and Maro.

These four brothers are known for having established the "four houses" of the Fujiwara.