Ryo Ishikawa (石川 遼, Ishikawa Ryō?, born 17 September 1991), also known by the nickname "Hanikami Ōji" (literally, "Bashful Prince"), is a Japanese professional golfer.
On 20 May 2007, Ishikawa became the youngest winner ever of a men's regular tournament on the Japan Golf Tour by winning the Munsingwear Open KSB Cup at the age 15 years and 8 months. He competed as an amateur and it was Ishikawa's first tour appearance. He finished one shot ahead of Japan's 9th top ranked player at the time, Katsumasa Miyamoto. The highest ranked player on the Official World Golf Ranking who took part in the event was Toru Taniguchi who finished T13, 6 shots shy of Ishikawa. Taniguchi ranked number 86 in the world after the event.
Ishikawa turned professional in 2008 and won another Japan Golf Tour tournament, the mynavi ABC Championship. By the close of 2008 he had become the youngest ever player to reach the top 100 of the Official World Golf Rankings.