Gillian Horn was born in Glasgow and took up the bassoon aged 10. She studied for both her Bacherlor and Masters' degrees at the Royal Conservatoire of Scotland, taking lessons from David Hubbard (RSNO), Peter Whelan (SCO) and Alison Green (SCO). A highly active ensemble player, she was successful in winning places on the coveted mentoring schemes with RSNO and SCO, the latter of which culminated in three highly acclaimed performances of Mozart's Gran Partita for Winds and a BBC Radio 3 broadcast. In 2018, Gillian was invited to join the SCO for their annual Highland summer tour.

Gillian has a particular love of opera and has been Principal Bassoon of Raucous Rossini opera company since 2015, touring the UK and Umbria (Italy) each summer. In 2018 she appeared as a soloist with RR performing Mozart's Sinfonia Concertante for Winds. She has also played as principal bassoon with New Generation Festival (Florence), Clyde Opera Group, Edinburgh Grand Opera and the Scottish Concert Orchestra.

An active chamber musician, Gillian has been a member of Sirocco Winds (wind quintet/trio) since 2016. Represented by Live Music Now Scotland and Classical Musicians Scotland, past performances have included St Magnus International Festival, Music at Paxton, Balerno Festival, and even aboard the Saga Pearl II in the entertainment team for the National Trust for Scotland.

Gillian is a grateful recipient of scholarships from Dewar Arts Awards, Musicians Benevolent Trust, Wolfson Trust, Craxton Memorial Trust and the EMI Music Sound Foundation.