He was a graduate of Kazimierz Brodziński High School in Tarnów (I Liceum Ogólnokształcące im.

Olszewski defended his doctoral dissertation at Heidelberg University, then returned to Kraków, where he was made profesor nadzwyczajny (associate professor).

[2] In 1884, in his Kraków laboratory, Olszewski was the first to liquefy hydrogen in a dynamic state, achieving a record low temperature of −225 °C (48 K).

Later on, in early February he provided an X-ray image of a luxated elbow thus initiating the university's department of radiology.

In 2018, his ashes were transferred to one of Poland's National Pantheons located at the Church of Saints Peter and Paul in the Old Town district of Kraków.