An alumnus of San Francisco Opera's prestigious Merola Opera Summer Program, Shannon began her operatic career as a member of the Canadian Opera Company Ensemble Studio Program. She has since gone on to perform major roles with the COC (Sesto in Sartorio's Giulio Cesare in Egitto, a Madrigalist in Henze's Venus and Adonis, Xenia in Boris Godunov, Oscar in Un ballo in maschera and Elvira in L'italiana in Algeri), l'Opéra du Québec, Opera Lyra Ottawa (Nanetta in Falstaff, Rosina in Il barbiere di Siviglia special school performance), Opera Ontario, Opera Atelier (Médée) and the Toronto Operetta Theatre. In July 2006 Shannon made her London debut under the auspices of the ROH Covent Garden in The Midnight Court with Toronto's Queen of Puddings Music Theatre.

Particularly praised for her performances of baroque and contemporary music, Shannon maintains a challenging balance of opera, concert and recital appearances. Her upcoming 2009-2010 season is no exception. She begins in Ottawa where she reprises her "achingly beautiful" Pamina in Opera Lyra's The Magic Flute. October sees Shannon at London's famed Royal Albert Hall for a performance of Eric Idle's highly popular Not the Messiah.

Highlights of her concert calendar include Carnegie Hall in New York for Bach's Christmas Oratorio with Les Violons du Roy, Roy Thomson Hall with the Toronto Symphony Orchestra for Handel's Messiah and concerts at the TSO's Mozart@254 Festival, Luc Beausejour's Clavecin en Concert, Generation Purcell in Houston with Mercury Baroque and Les Voix Baroques, in Montreal for Handel's German Arias with Les Idées Heureuses, St Matthew Passion with the Ottawa Choral Society and a concert with her JUNO Award partners, Ensemble Caprice, in March.

Performances as Pamina in Die Zauberflöte figured prominently on Shannon's 2008-2009 calendar - her role debut as Pamina with Opera Hamilton was greeted with praise: "beautiful tone, pure and steady, she was a delight" (Hamilton Spectator). Her reprisals of the role with the Pacific Opera production in Victoria and London were no different: "Shannon Mercer's Pamina is tender, guileless and, in her moments of anguish, deeply moving" (Victoria Times Colonist). She also sang First Lady in the Toronto Symphony concert presentation of the same opera, conducted by Bernard Labadie and in the world première of Inês, a new opera by James Rolfe presented by the Queen of Puddings Theatre. A highlight of Shannon's 2008-2009 concert calendar was the launch of her new recording Wales ~ The Land of Song (Analekta) in Ottawa on March 8th with the Skye Consort. Other appearances included a concert at the Glenn Gould Studio under the auspices of OffCentre Music Series, performances of the Messiah with the Vancouver Chamber Choir, Charpentier's Messe de Minuit with Les Violons du Roy, and Bach's Mass in G Major and Cantata 51 with Symphony Nova Scotia.

Recent engagements include her return to the Canadian Opera Company as Despina in Mozart's Così fan tutte, performances of Handel's Messiah in Vancouver, Calgary and Montreal, her debut in France with the Opéra national de Montpellier, in the title role of Marin Marais's French Baroque opera Sémélé. She has also appeared in Handel's Israël en Égypte with Les Violons du Roy in Montréal and Québec City, debuted at Alice Tully Hall, Lincoln Center in an all-Mozart recital featuring renowned American soprano Barbara Bonney, peformed at the Ottawa International Chamber Music Festival, in solo recital with Music Toronto for The Discovery Series and in a Schubertiade recital with the Aldeburgh Connection at the Glenn Gould Studio in Toronto.

In June 2007 Shannon appeared in the world premiere of Eric Idle's new comic oratorio Not the Messiah with the Toronto Symphony Orchestra under Peter Oundjian both at Toronto's first Luminato Festival and at the Caramoor Festival. She reprised the role in a US tour to Houston, Washington, and Los Angeles' Hollywood Bowl in the summer of 2008.

Shannon's award-winning discography includes several releases on the Analekta label: the 2009 JUNO Award recipient Gloria!: Vivaldi's Angels with Ensemble Caprice, the JUNO nominated Bach and the Liturgical Year and Mondonville with harpsichordist Luc Beauséjour, and English Fancy, a disc of songs by Purcell, Campion and Jenkins. Her much-lauded French debut in the title role of Marin Marais's Sémélé is part of the renowned Hérve Niquet/Le Concert Spirituel trilogy of tragédie lyriques on Glossa: "Mercer's Semele seduces" (BBC Music Magazine). She also starred in Alexina Louie's Gemini-nominated comic opera Burnt Toast, an 8-vignette series directed by Larry Weinstein that was presented at the Toronto and Calgary film festivals and broadcast nationally on CBC television and Bravo!.

Awarded a Career Development Grant from the Canada Council for the Arts and winner of the 2004 Bernard Diamant Prize, Shannon spent most of 2005 in Vienna where she studied German operatic repertoire with renowned voice coach Margaret Singer. She has recently received the Virginia Parker Prize from the Canada Council for the Arts and the Women's Musical Club of Toronto Career Development Award.

A native of Ottawa, Shannon Mercer now resides in Toronto.