The mezzo-soprano Sophie Marilley was born in Fribourg, studying at the Conservatory there and working in masterclasses with Irvin Cage, Brigitte Fassbaender and Anthony Rolfe Johnson.
She joined the Antwerp Opera Studio in 2001–02 and in 2002 was a prize winner in the International Hans Gabor Belvedere Singing Competition in Vienna.
From 2001 to 2005 she was a member of the Osnabrück State Theatre, where she appeared as Octavian (Der Rosenkavalier), La Cenerentola and La Périchole, with guest appearances at the Antwerp Flemish Theatre, the St Gallen Theatre, the Lisbon Teatro Nacional de São Carlos, and as Cherubino (Le nozze di Figaro) and Prince Charmant (Cendrillon) at the Théâtre Royal de La Monnaie in Brussels. From 2006–07 she was a member of the Vienna State Opera, with roles including Cherubino, Siebel (Faust) and Stéphano (Roméo et Juliette). From 2011 to 2017 she was a permanent member of Stuttgart Opera with roles including Donna Elvira (Don Giovanni), Alise (Der Schaum der Tage), Dorabella (Così fan tutte) and Nicklausse (Les contes d‘Hoffmann). In 2017–18 she returned to Stuttgart Opera, singing Siebel in Faust and Elvire in the premiere of Hosokawa’s Erdbeben.Träume.