Wakatsuki Reijirō (若槻 礼次郎 Wakatsuki Reijirō) (March 21, 1866 - November 20, 1949) was a Japanese politician and the 25th and 28th Prime Minister of Japan. His first term lasted from January 30, 1926 to April 20, 1927; the second from April 14, 1931 to December 13, 1931. He was born in Matsue of Izumo province, now called Matsueshi in Shimane Prefecture. Opposition politicians of the time labeled him "Reijiro the Liar". The offical representation of his name in Chinese characters is (禮次郎) Reijirou.

He was born in Matsue of Izumo province, now called Matsueshi in Shimane Prefecture. His father was named Okumura, a samurai who served the Matsudaira clan. Later Wakatsuki married a woman of the Wakatsuki clan who adopted him since the clan had no male heir.

He enrolled in the Tokyo Imperial University in 1892 and studied law. After graduation, he worked in the Ministry of Finance and eventually rose to position of second minister. In 1911 he was appointed a senator in the Kizoku-in . He was then appointed as the Minister of Finance under Katsura Taro and Okuma Shigenobu in the early 1910's.

He opposed aggression with United States before World War II and after declaration of hostilities, publically stated the war should end as quickly as possible.