Tomasz Jeż studiował muzykologię w Warszawie, Getyndze i Berlinie (jako stypendysta DAAD). Po promocji doktorskiej (2002) został zatrudniony na Uniwersytecie Warszawskim. W ramach programu „Kolumb” Fundacji na rzecz Nauki Polskiej odbył w roku 2007/08 staż naukowy w Archivum Romanum Societatis Iesu. Jest autorem trzech książek i ponad sześćdziesięciu artykułów, poświęconych zagadnieniom źródłoznawczym i ideowym aspektom kultury muzycznej. Jego głównym polem badań jest kultura muzyczna Śląska oraz Polski w XVI, XVII i XVIII wieku.  

Tomasz Jeż studied musicology in Warsaw, Göttingen and Berlin (with DAAD scholarship). After his PhD promotion (2002) he was employed as assistant professor at the Institute of Musicology, University of Warsaw. For the academic year 2007/8 received the postdoc scholarship of the Foundation for Polish Science for the scientific stage in Archivum Romanum Societatis Iesu. He wrote three books and 60 papers, concerning heuristic and spiritual contexts of the music culture. His main field of interest is the music culture of the Silesia and the Polish-Lithuanian Commonwealth in the 16th-18th c.

He is a leader of the scientific project The Music Repertoire of the Society of Jesus in the Polish-Lithuanian Commonwealth (1565–1773), financed by the Ministry of Science and Higher Education  Republic of Poland as a part of the „National Programme for the Development of Humanities”. The effects of this grant project activity are published in the series Fontes Musicae in Polonia (www.fontesmusicae.pl), which includes the catalogues of the music collections, facsimile editions, books on history of music, and music scores from the territory of the old and present-day Polish state.