Seiichi Ōmura (大村 清一, Ōmura Seiichi, 4 May 1892 – 24 May 1968) was a politician and bureaucrat in the early Shōwa period Japan, who subsequently was a politician and cabinet minister in the immediate post-war era.

After his graduation from the Law School of Kyoto Imperial University, he entered the Home Ministry.

After the end of World War II, during the American occupation of Japan, Ōmura served as Home Minister in the first Yoshida administration from 22 May 1946 to 24 May 1947.

From 10 December 1954 to 19 March 1955, Ōmura served as Director-General for the Japan Defense Agency under the first Hatoyama administration.

Ōmura subsequently was elected a seat in the Lower House of the Diet from his native Okayama, and served for six terms from 21 November 1960 to 23 October 1963.