He was born in Oban and spent his early years in Inveroran, near Bridge of Orchy (hence his first album title). His father Billy was an accomplished musician, as is his mother Agnes, and his grandfather was the late Pipe Major Ronnie McCallum MBE, piper to the Duke of Argyll. At the age of four the family moved to Moffat in Dumfriesshire where Stuart went to school. The family moved to Inveraray, his mother's home town, in 1983.
Liddell lives in Inveraray and is Pipe Major of the Grade 1 Inveraray & District Pipe Band—a band he helped found. For ten years (1998–2008), he played with the Simon Fraser University Pipe Band in Burnaby, British Columbia. With the SFU Pipe band he won three World Pipe Band Championship titles, in 1999, 2001, and 2008. Before joining the SFU Pipe Band, he played with ScottishPower Pipe Band.
Liddell has won many of the top awards in solo piping, including the Gold Medal at the Argyllshire Gathering (2000), the Gold Medal at the Northern Meeting (2004), the former winner's Clasp at the Northern Meeting (2007 & 2009), the Bratach Gorm at the Scottish Piping Society of London (2009) and
He is known for his fast playing and innovative arrangements of piping standards.
In 2007, Liddell released his first solo recording, Inveroran. He has also appeared on several recordings of Simon Fraser University Pipe Band, with solo tracks on many discs.
- "Entertainment: SFU Pipe Band makes its annual call to Vernon". The Morning Star. 3 July 2015.
- "Pipe Band History and Accolades". Simon Fraser University Pipe Band. April 2014. Retrieved 8 October 2015.
- "Andrew's Tips: Gold Medal Winners". BagpipeJourney. Retrieved 26 July 2013.
- "Northern Meeting Winners". The Northern Meeting. Retrieved 26 July 2013.
- "Music review: Glenfiddich Piping Championship". The Scotsman. 2 November 2009. Retrieved 8 October 2015.
- "Piper lifts 'ultimate accolade'". BBC News. 1 November 2009.
- "Glenfiddich piping and fiddle champions crowned". BBC News. 26 October 2014.