Rachael Margaret Grinham (born 22 January 1977 in Toowoomba, Queensland) is a professional squash player from Australia. She won the World Open in 2007, and the British Open in 2003, 2004, 2007 and 2009. She reached the World No. 1 ranking in August 2004 and held it for 16 consecutive months. Rachael's younger sister Natalie Grinham is also a top squash player.