Born in Gdansk, Jaga Klimaszewska began studying violin at the age of seven.

After graduating from the F.Nowowiejski Music School in Gdansk in 2009, she moved to London to continue her musical studies.

Jaga obtained her Bachelor of Music Diploma from Guildhall School of Music and Drama in 2013 where she studied with Krzysztof Smietana. Jaga completed a Master of Performance at the Royal College of Music under the tutelage of Maciej Rakowski. She received the RCM Award and G.D. Fahrenheit Educational Scholarship awarded by the Mayor of Gdansk.

She performed as a soloist with Cappella Gedanensis, Camerata Baltica and Silk Street Sinfonia.

Over the years, Jaga has worked with numerous well-known artists including Maxim Vengerov, Leonid Kerbel, Peter Schuhmayer, Vasko Vassilev, Peter Herresthal, David Takeno, Barnabas Kelemen, Carole Presland, Belcea Quartet, The Gould Piano Trio, and Heath Quartet.

In 2019, together with pianist Mateusz Rettner, she released her debut album featuring music by Grazyna Bacewicz. In 2021, she started the Women in Music Festival together with the Polish Chamber Musicians Association. She has been leading the Fidelio Orchestra since March 2024.