Takehiro Ishii (石井 丈裕, born October 25, 1964) is a Japanese professional baseball pitcher. He played in Nippon Professional Baseball and for the Japan national baseball team.
Ishii attended Waseda Jitsugyo High School and Hosei University. He pitched for the Seibu Lions from 1989 through 1997, and the Nippon Ham Fighters in 1998 and 1999. He was named Most Valuable Player of the Pacific League in 1992.
Ishii played for the Japanese national baseball team at the 1988 Summer Olympics and the 1988 Baseball World Cup. He led all pitchers in the 1988 Cup in strikeouts (32 in 27 1/3 IP), beating out the likes of Andy Benes, Ben McDonald, Charles Nagy, Jim Abbott, Hideo Nomo and Orlando Hernandez. Ishii went 3–0 with a save and a 0.99 ERA. He allowed only two walks and 15 hits. He joined Abbott as the tourney's All-Star pitchers. He tried to save the semifinals after Nomo faltered in the 8th but allowed a single, triple and a balk without retiring anyone in the loss to Cuba that eliminated Japan.