| Osanori Koyama | |
| Native Name Lang: | ja |
| Native Name: | 小山 長規 |
| Alma Mater: | University of Tokyo |
| Birth Date: | 10 June 1905 |
| Birth Place: | Miyazaki Prefecture, Japan |
| Office1: | Member of the House of Representatives |
| Constituency1: | Former Miyazaki 2nd District |
| Office2: | Minister of Construction |
| Term Start2: | July 18, 1964 |
| Term End2: | June 3, 1965 |
| Primeminister2: | Hayato Ikeda, Eisaku Satō |
| Predecessor2: | Ichirō Kōno |
| Office3: | Director General of Environment Agency (Minister of State) |
| Term Start3: | July 7, 1972 |
| Term End3: | December 22, 1972 |
| Primeminister3: | Kakuei Tanaka |
| Successor3: | Takeo Miki |
was a Japanese politician, a member of the National Diet and a Cabinet member.
He was born in Kobayashi, Miyazaki.[1] [2] He graduated from Kagoshima Prefectural Daini-Kagoshima Middle School (now Kagoshima Prefectural Konan High School) in 1923 and from Third Higher School (now Kyoto University) in 1926.
In 1929, he graduated from Faculty of Law, Tokyo Imperial University (now University of Tokyo) and joined Mitsubishi Bank. Later, he served as the committee chairs of Mitsubishi Bank Employees' Union.
He was first elected to a member of the House of Representatives in 1949 and was elected 12 times. He served as Minister of Construction in the Cabinets of Hayato Ikeda and Eisaku Satō, Director General of Environment Agency in the Cabinet of Kakuei Tanaka, the chief of Judge Impeachment Court, and the Chairs of Committee on Agriculture, Forestry and Fisheries and Committee on Budget of the House of Representatives. He received the Grand Cordons of the Order of the Rising Sun in 1976.