Baron Uchiyama Kojirō (内山小二郎, 14 November 1859 – 14 February 1945) was a general in the early Imperial Japanese Army.

He became chief-of-staff of the IJA 1st Division in February 1895; however, he returned to Japan in May and was sent as a military attaché to Russia in December of the same year.

In January 1901, Uchiyama became commander of the IJA 15th Field Artillery Regiment, and was promoted to major general in June of the same year.

In November 1921, Uchiyama was ennobled with the title of baron (danshaku) under the kazoku peerage system.

He entered the reserves in 1923 and was promoted to the honorific title of Junior Second Court Rank[2] He retired in 1929 and died in 1945.