She was born on 24 December 1926 in Mońki, Second Polish Republic, to father Cyprian Janion and mother Ludwika (née Kurdyk).

After the events of March 1968, she was dismissed from her position at the WSP as the communist authorities were concerned about her growing influence on the university students.

Her lectures placed emphasis on revolutionary and libertarian aspects of Romanticism which did not adhere to the official and generally accepted interpretation of the literary canon and encouraged her students to adopt a bold, defiant and original perspective on Polish literature.

Her independent opinions, which won respect among students and academic members, as well as her connections to the opposition, caused her to become a potential enemy of the state.

[4] When the Solidarity movement began, Janion signed the letter issued by 64 intellectuals supporting the strikes, yet calling for actions that would not contribute to bloodshed.

She stressed that in Romanticism with time there is increasing importance of a sense of the absurd and grotesque with regard to existence, expressed in irony and melancholy.

She traces the birth of Romanticism to the re-discovery of the modern "self", which in the beginning primarily manifested itself in individualism exploring the experience and the mystery of a particular existence.

However, in her work The Romantic Fever, she demonstrates that Romanticism could not hold itself to a static and unambiguous system — not even among its epigones, since they merely reinforced its antinomies and transformed them into stereotypes.

[7] In her books, she discussed numerous aspects of this new paradigm such as the new Romantic hero; a radical violation of the death taboo; re-exploration of the hidden and forgotten which led to the ennobling of vernacular cultures (folk culture in particular, but also pagan, Slavic, Nordic and Oriental cultures); the concept of nature as a model; a mode of existence which in an inevitable way identifies creation with destruction or even self-destruction and life with death; the understanding of history as a theophany; the dramatic philosophy of existence stretching from salvation to nothingness; as well as suppressed existential experiences (that of a child, madman or a woman).

In the book Niesamowita Słowiańszczyzna ("Uncanny Slavdom"), Janion deployed Edward Said's concept of Orientalism to prove that in the Middle Ages Western Slavs underwent colonization by Roman Catholicism.

According to Janion, Poles entering the realm of Latin influence severed them from pagan tradition and has become for them a source of trauma, which continues to affect their present collective identity.