[2] Murdoch rose to prominence when he won the gold medal in the 200 metre breaststroke at the 2014 Commonwealth Games in Glasgow, beating favourite, Olympic silver medalist and fellow Scot Michael Jamieson.

In 2015, he formed part of the Great Britain squad that won gold in the mixed 4 x 100 metre medley relay at the 2015 World Aquatics Championships, swimming in the qualifying heats, and adding a relay world title to the individual bronze won days earlier in the men's 100 metre breaststroke behind teammate Adam Peaty.

Ross' first notable performance was in the 200 m breaststroke final at the British Gas Swimming Championships 2012 where he achieved a seven-second personal best[3] at the London Aquatics Centre.

In 2015, he claimed the bronze medal in the 100m breaststroke, placing third behind fellow British teammate Adam Peaty and South African Cameron Van Der Burgh with a time of 59.09.

He qualified (coming first) for the final of the 200 metre breaststroke with fellow Scots, favourite Michael Jamieson and Calum Tait.

[10] At the 2022 Commonwealth Games, held starting in July in Birmingham, England, Murdoch won a bronze medal in the 200 metre breaststroke on the first day of swimming competition with a time of 2:10.41.