Grímur Helgason studied clarinet with Sigurður I. Snorrason at the Reykjavík College of Music and with Einar Jóhannesson at the Iceland University of the Arts, graduating in 2007. Upon completing his studies, he was selected as a prizewinner in the Young Soloists Competition and was also awarded a grant from the Halldór Hansen Memorial Fund. During his student years, Grímur was one of the founding members of the Ísafold Chamber Orchestra. He later continued his studies with Hans Colbers at the Conservatorium van Amsterdam, where he completed a Master of Music degree in the spring of 2011.

In recent years, Grímur has been active across a wide range of Icelandic musical life as a chamber musician, orchestral player and performer of contemporary music. He is a permanent member of the Iceland Symphony Orchestra and has performed regularly with ensembles including Caput, Stirni Ensemble, Kúbus, Cauda, the Reykjavík Chamber Orchestra and the Icelandic Opera Orchestra. He has also collaborated with a diverse range of composers and fellow instrumentalists.