Robert Peter Renwick (born 21 July 1988) is a Scottish former competitive swimmer who represented Great Britain at the Olympics and FINA world championships, as well as Scotland in the Commonwealth Games.

He first rose to prominence by swimming the anchor leg in the Scottish men's 4×200-metre freestyle relay team at the 2006 Commonwealth Games as a 17-year-old.

He achieved this by finishing second, behind Ross Davenport, in the 2008 Long Course British Championships (incorporating the Olympic trials).

Renwick won the gold medal in the 200 m freestyle at the 2010 Commonwealth Games in Delhi, India.

His greatest success came in the 2015 World Championships in Kazan, Russia where Renwick, along with Dan Wallace, Callum Jarvis and James Guy beat the United States in the men's 4×200 m freestyle.