Robert 'Bob' Thornton (born 17 July 1967) is a Scottish professional darts player.

Thornton is a three-time major winner between the BDO and PDC, having won the World Masters in 2007, UK Open in 2012, and World Grand Prix in 2015. He is also a former finalist at the Players Championship Finals in 2009 and Grand Slam of Darts in 2013. In addition, Thornton has reached three World Championship quarter-finals across both organisations and was a participant in the Premier League in 2013, 2014 and 2016. He managed to achieve a televised nine dart finish in the 2014 World Grand Prix against James Wade.