Leszczyna graduated in Polish philology at the Jagiellonian University in Kraków.

In 2006, she was elected to Częstochowa City Council from the Civic Platform.

[1] In 2010, in the elections for the office of President of Częstochowa, she obtained the second result (21.99%).

In the second round of elections, she obtained 29.11% of votes and was defeated by Krzysztof Matyjaszczyk.

[2] In December 2023, she was appointed as the Minister of Health in Donald Tusk's third cabinet.