Toshiki Mabuchi (kanji: 満渕俊樹, hiragana: マブチ トシキ, Mabuchi Toshiki, born in 1950) is a Japanese mathematician, specializing in complex differential geometry and algebraic geometry.[1] In 2006 in Madrid he was an invited speaker at the International Congress of Mathematicians.[2] Mabuchi is known for introducing the Mabuchi functional.