Toshihiro Nikai (二階 俊博, Nikai Toshihiro?, born February 17, 1939) is a Japanese politician. He is currently the Minister of Economy, Trade and Industry. A member of the Liberal Democratic Party (LDP), Nikai is currently serving in his eighth term in the Lower House representing Wakayama's Third District.

Nikai was born in Wakayama Prefecture and attended Chuo University, graduating with a law degree in 1951. He initially worked as secretary for Saburo Endo, a Diet member from Shizuoka. After Endo's death, Nikai returned to Wakayama, where he won a seat on the prefectural assembly in 1975. He was elected to the House of Representatives in 1983.

He was a member of Noboru Takeshita's faction within the Liberal Democratic Party, but left the party in 1993 to join the Japan Renewal Party (Shinseitō). As a member of the JRP, he served as Vice-Minister of Transportation under Morihiro Hosokawa in 1999.