Mikael Onelius received his education at the Birmingham Conservatoire, the Royal College of Music and the College of Opera in Stockholm.
Mikael has been employed at the Royal Swedish Opera since 2018 and before that he sang at the Göteborg Opera, Garsington Opera, Buxton Opera Festival and others. Previous roles include Tamino (Die Zauberflöte/Hälsingeoperan), Malcolm (Macbeth/Göteborg Opera), Claudio (Das Liebesverbot/Kamraterna), Apollo (Semele/Garsington Opera), Lensky (Eugene Onegin/College of Opera).
Mikael was the 2015 winner of the Gothenburg Wagner Society's Bayreuth Scholarship.