Ōkubo Tadatomo (大久保 忠朝, December 24, 1632 – October 25, 1712) was a daimyō in early Edo period, Japan.
Due to the early death of his father, Tadatomo was adopted by his brother Ōkubo Tadamoto, the 1st daimyō of Karatsu, whom he served as a page.
His revenues were increased by 10,000 koku in 1680 and his courtesy title was elevated to Chamberlain.
In 1684, the Tairō Hotta Masatoshi was assassinated by wakadoshiyori Inaba Masayasu, and his cousin Inaba Masamichi was punished by demotion from Odawara Domain to the much smaller Takada Domain in Echigo Province.
The Shiba Rikyu gardens in Tokyo were originally built on the Edo residence of Ōkubo Tadatomo in 1678, when he entertained Shogun Tokugawa Ieshige.