Mimi Coertse, was born in Durban and matriculated at the Hoër Meisiesskool Helpmekaar in Johannesburg. In 1954 she began her studies at the Academy for Arts and Science in Vienna.

One year later she debuted in Napels, with the Vienna State Opera, as a Flower maiden in Wagner's Parsifal, under Karl Böhm. In 1956 she made her debut as Queen of the Night in Mozart's Die Zauberflöte in the Vienna State Opera, and repeated at Covent Garden - London the same year. During 1956 she also sang in the Salzburg Festspiele as Konstanza in Die Entfuhrung aus dem Serail.

She became the youngest permanent member of the Vienna State Opera, where she remained for more than two decades. Her repertoire expanded rapidly to include such roles as Gilda from Rigoletto, Lucia from Lucia di Lammermoor and Violetta from  La Traviata to name a few. In her operetta repertoire Hanna Glawari from Die Lustige Witwe and Rosalinde from Die Fledermaus lingers in the mind.
    
In 1966 she was honoured with the title Kammersängerin of Austria.
In 1961 she was awarded the Medal of Honour of "Die Suid-Afrikaanse Akademie vir Wetenskap en Kuns"and in 1985 she received the Decoration for Meritorious Service in recognition of her contribution to the Arts.

Mimi Coertse is not only a great interpreter of the German lieder, but also had the ability to sing the Afrikaans lied with such devotion that it reminds one of the Schubert and Schumann lieder.

Since returning to South Africa in 1973 she has been a regular guest  on South African stages, having been seen throughout the country in opera, operetta and on the concert and recital platform. She has additionally been a frequent broadcaster, on radio and television.

Her support for her fellow South African musicians has been outstanding - as may be witnessed in her Debut with Mimi series and in the Mimi Coertse Bursary.  The winners of the series and bursaries, which were chosen by Ms Coertse, that are currently performing aboard and locally are:  Johann Botha, Michelle Breedt, Andrea Catzel, Kobie van Rensburg, Virginia Davids, Jannie Moolman, Hanli Stapela, Raphael Vilakasi, Marisa Vitali, Musa Nkuna, George Stevens, Sharon Rostorf, Sibongile Mngoma to name a few.

In August 1996 she received the highest accolade that an artist can receive from the Austrian Goverment: the Österreichishes Ehrenkreuz für Wissenschaft und Kunst.  In September 1998 she received the D.Phil (h.c) from the University of Pretoria.

In 1999, Mimi Coertse and Neels Hansen, celebrated opera director and costume designer, founded The Black Tie Ensemble. For the past twelve years Ms Coertse has been closely associated with The Black Tie Ensemble and works with the young artists to prepare them for opera careers abroad and locally.  One such artist that is currently singing abroad is the bass, Vuyani Mlinde.   

In 2009, she received a Sepecial Kanna Award for life time achievement for performing at the KKNK.

Mimi Coertse’s performing career span over 40 years of which she performed 469 times in 27 different roles at the Vienna State Opera.  Mimi Coertse is one of South Africa’s greatest icons of all time and she will always be Onse Mimi.