Estonian mezzo-soprano Kai Rüütel studied at the Georg Ots Music School in Tallinn and then at the Koninklijk Conservatorium in The Hague and the Dutch National Opera Academy, graduating from the Masters programme with Special Honours. Whilst studying in the Netherlands she was supported by Eesti Kultuurkapital. Rüütel won First Prize in the National Competition for Young Classical Singers in Estonia three years in a row in 2001, 2002 and 2003.
In 2009 Rüütel became a member of the prestigious Jette Parker Young Artists Programme at the Royal Opera House, Covent Garden, making her Royal Opera House debut as Venerable Lady in The Gambler and covering the role of Blanche. Her roles for the company included Hansel Hansel 
und Gretel, Rosette Manon and Flora La Traviata (also performed on tour in Japan), Second Lady Die Zauberflöte conducted by Sir Colin Davis, and Dorothée Cendrillon. She covered Madame Dangeville Adriana Lecouvreur, Charlotte Werther and Dunyasha The Tsar’s Bride. 
Since leaving the programme she returned to the Royal Opera House as Meg Page Falstaff in a new production by Robert Carsen and as Marchesa Malibea Il Viaggio a Reims in a special gala performance. She also made her debut with Scottish Opera as Hansel Hansel und Gretel. Recent concert engagements include Mahler Rückert Lieder at the Cadogan Hall and her Berlin debut at the Philharmonie with a programme of Zemlinsky and Mahler songs. 
Last season Kai Rüütel returned to the Royal Opera House as Wellgunde Der Ring des Nibelungen and made her US debut with the St Louis Symphony Orchestra singing Mozart Requiem. Other highlights included her City of Birmingham Symphony and Philharmonia orchestras debuts singing Beethoven Mass in C, a series of gala concerts in Latvia and the Czech Republic as well as her first Dream of Gerontius for The Three Choirs Festival. 
In 2013/2014 she appears as Blanche in a new production of The Gambler at De Nederlandse Opera, Sonyetka in a new production by Calixto Bieito of Lady Macbeth from the Mtsensk District at Vlaamse Opera and Siegrune Die Walküre at Gran Teatre del Liceu. On the concert platform she makes her debuts with Residentie Orchestra Netherlands singing Beethoven’s Ninth Symphony and with RTE Orchestra and John Wilson in a special Opera Gala Concert. 

Her voice sounded absolutely gorgeous. Throughout her performance she exhibited a marvellous sense of line and her voice was produced not only evenly throughout its compass but also seemingly without effort. Time and again there was lovely warmth to her singing… 

 Seen and Heard International, August 2013