Born in 1990 in Graz, Austria, mezzo-soprano Sophie Rennert had violin lessons from the age of five, later adding piano lessons at the J.J. Fux conservatory in Graz. In 2002, she began her voice studies with her mother Sigrid Rennert, a singing teacher and a soprano in her own right.

She graduated from high school (PG Ursulinen) in 2008, with honours; at the time, she had already been a member of the TaO! ensemble (Theatre at the Ortwein Square, Graz) for two years. Since fall 2008, she studies at the Vienna University of Music and Performing Arts under Professor Karlheinz Hanser. Two years later she received her "first diploma", a required stepping stone on the way to completing a course of study, with honours. As part of the Eppaner Liedsommer (Summer of Song festival in Eppan) she completed a master class under Ks Brigitte Fassbaender.

Sophie Rennert has repeatedly been awarded the first prize of the Austrian national competition Prima La Musica. She won the first prize in the Gradus ad Parnassum competition 2011 and the KlassikPreis.Österreich (ClassicPrize Austria) 2011. In January 2012, Rennert added a first prize at the Musica Juventutis competition to her successes and has therefore been invited to give a recital at the Vienna Konzerthaus during the season 2012/13.

Participating in the "Serenades in Bruck an der Mur" (Austria), she played Bastien (W.A. Mozart: "Bastien and Bastienne") in 2009 and Crôute-au-pot (J. Offenbach: "Mesdames de la Halle") in 2007. The Neue Studiobühne in Vienna saw her in 2010 as Celia (J. Haydn: "La fedeltà premiata") and in 2011 as Diana (C.W. Gluck: "Iphigénie en Tauride"). In 2011, she also sang Mrs. Noye in Britten's "Noye's Fludde" at the House of Art in Muerz and, in the theatre of Schönbrunn Palace in Vienna, the title role in a scenic version of Händel's oratorio "Susanna".

Rennert also has performed concerts and sacred music in numerous engagements both at home and abroad.