Eliška Weissová graduated from the Brno Conservatory and the Prague Academy of Music under René Tuček. She attended masterclasses of Nadězda Kniplová and Peter Dvorský. She won prizes at several singing competitions, including first prize at the Antonín Dvořák International Singing Competition in Karlovy Vary (2004) and third prize at the Mikuláš Schneider-Trnavský Singing Competition in Slovakia (2006), was a semi-finalist at the Competizione dell'opera in Dresden and a finalist at the Boris Christoff Competition in Sofia.
Since 2006 she has been a regular guest of the National Theatre Prague, National Theatre Brno, Theatre Plzeň, Theatre Ústí nad Labem, Opava, State Theatre Košice and Slovak National Theatre Bratislava.
Internationally, Eliška Weissová performed at the opera festival in Wexford, Ireland as Martinka (Smetana: The Kiss), at the Opéra de Rennes, Opéra-Théâtre de Limoges and Grand-Théâtre de Reims as Kostelnička (Jenůfa), at the Opéra de Rennes also as Rossweisse (Die Walküre) and Ulrica, at the Slovak National Theatre as The Foreign Princess and the Witch (Rusalka), at the Erfurt Theatre as Azucena and Amneris and with the Bayreuth Festival as Rossweisse (Walküre) in Abu Dhabi.
In 2018, she successfully made the transition to dramatic soprano when she gave her debut as Giorgetta (Il tabarro) at the National Theatre in Bratislava. This was followed by a number of other roles, including Libuše (Smetana) at the North Bohemian Theatre in Ústí nad Labem, Fata Morgana (The Love for Three Oranges), Ortrud (Lohengrin, directed by Katarina Wagner) and Kostelnička (Jenůfa) at the National Theatre Prague, where she made her debut as Turandot (Turandot) in February 2020 and Abigaille (Nabucco) in September 2020.
In October 2019, Eliška Weissová appeared as Amneris in a new production of Aida at the historic Hatshepsut Temple complex in Luxor (Egypt) under the baton of Oksana Lyniv. In September 2022, she made her debut as Isolde (Tristan and Isolde) at the North Bohemian Theatre Ústí nad Labem.In March 2022, she gave her house debut at the Welsh National Opera as Kostelnička (Jenůfa) under the baton of Tomáš Hanus, and will return as Milada in Dalibor (B. Smetana) in the 2024/25 season. In October 2022 she gave her house debut at the Wiener Staatsoper as Kostelnička (Jenůfa) under the baton of Tomáš Hanus,and will return as Foreign Princess in Rusalka (A. Dvořák) in the 2023/24 season.