| Tadahiko Okada | |
| Native Name Lang: | ja |
| Office: | Speaker of the House of Representatives |
| Term Start: | 25 May 1942 |
| Term End: | 9 April 1945 |
| Predecessor: | Ichimin Tako |
| Successor: | Toshio Shimada[1] |
| Office1: | Minister of Health and Welfare |
| Primeminister1: | Kantarō Suzuki |
| Term Start1: | 7 April 1945 |
| Term End1: | 17 August 1945 |
| Predecessor1: | Katsuroku Aikawa |
| Successor1: | Kenzō Matsumura |
| Office2: | Vice-Speaker of the House of Representatives of Japan |
| Term Start2: | 1 May 1936 |
| Term End2: | 31 May 1937 |
| Predecessor2: | Etsujirō Uehara |
| Successor2: | Tsuneo Kanemitsu |
| Office3: | Governor of Kumamoto |
| Term Start3: | 1922 |
| Term End3: | 1923 |
| Predecessor3: | Sanosuke Nakayama |
| Successor3: | Chisato/Senri Tanaka |
| Office4: | Governor of Nagano |
| Term Start4: | 1921 |
| Term End4: | 1922 |
| Predecessor4: | Tenta Akaboshi |
| Successor4: | Toshio Honma |
| Office5: | Governor of Saitama |
| Term Start5: | 1916 |
| Term End5: | 1919 |
| Predecessor5: | Akira Sakaya |
| Successor5: | Yasuyoshi Nishimura |
| Birth Date: | 21 March 1878 |
| Birth Place: | Okayama, Japan |
| Alma Mater: | Tokyo Imperial University |
was a Japanese politician. He was governor of Saitama Prefecture (1916-1919), Nagano Prefecture (1921-1922) and Kumamoto Prefecture (1922-1923).
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