Tania Giannouli was born in Athens in 1977. She studied piano, Advanced Theory and Composition at the Athenaeum and Orfeion conservatories. Being interested in mixed-media, she often takes part in projects that combine music with visuals, text and speech. Her own compositions for theatre, film and video have been performed at festivals, galleries, art Biennales and museums throughout the world.

She has collaborated with several award-winning video artists and filmmakers, including Istvan Horkay and Marcantonio Lunardi. She was one of the founder members of the groups 4+1 and Schema Ensemble.
The collaboration with Portuguese wind player and improviser Paulo Chagas resulted in her debut release on the New Zealand based label Rattle records in 2012.

Since then, she has been releasing with this label, featuring her own, original compositions which combine elegantly elements of jazz with a variety of genres and styles. On each ne of the recording she has worked with a different group (the Tania Giannouli Ensemble in 2014, the duo with Maori musician Rob Thorne in 2017, the Tania Giannouli Trio in 220).

She has played at international music festivals such as the Enjoy Jazz festival, the Jazzfest Berlin and the Festival Internacional de Jazz de Madrid. In August 2016, she participated in a extraordinary site-concert in Greece called "634 minutes inside the volcano" where, along with 14 more musicians, they improvised for more than 10 hours inside the crater of the island of Nisyros active volcano.

In 2021 Tania Giannouli was nominated for the Deutscher Jazzpreis- German Jazz Prize in the category "Piano/Keyboards International" together with Tigran Hamasyan and Shai Maestro.