Richard Mark Ranby (born 1 June 1977) is a former New Zealand rugby union player. A midfield back, Ranby represented Manawatu, the Central Vikings and Waikato at a provincial level, and the Hurricanes and the Chiefs in Super Rugby. He played one international for the New Zealand national side, the All Blacks, against Samoa in 2001. He played for the Japanese side Coca-Cola West Red Sparks for two seasons from 2006. He spent a year studying at the University of Cambridge in 2008–09, completing a Diploma in Theology and Religious Studies, and played for Cambridge against Oxford in the 2008 Varsity Match. In 2012 he was appointed professional development manager for the Crusaders and Canterbury Rugby.
Ranby's mother, Margaret Kouvelis, was elected Mayor of Manawatu in 2012.