[3] His father, Zbigniew Ryszard Grabowski né Abrahamer [pl], a Holocaust survivor and chemistry professor[4] from Kraków, fought in the 1944 Warsaw Uprising.

[5] While at the University of Warsaw, Grabowski was active in the Independent Students' Union between 1981 and 1985, where he helped to run an underground printing press for the Solidarity movement.

[9] In 2018, Grabowski and Barbara Engelking co-edited a two-volume study, Dalej jest noc: losy Żydów w wybranych powiatach okupowanej Polski (Night without End: The Fates of Jews in Selected Counties of Occupied Poland).

[21] However, scholars associated with Poland's Institute of National Remembrance alleged that the study used unreliable sources, selectively treated witness statements, presented rumor as fact, and underestimated the draconian nature of the German occupation.

[27][28] The POLIN Museum stated that the suit had been "an attempt to frighten scholars away from publishing the results of their research out of fear of a lawsuit and the ensuing costly litigation.

[31] In 2023, Grabowski and historian Shira Klein published an article in the Journal of Holocaust Research which stated that Wikipedia spread misinformation about the history of Jews in Poland due to the work of a small group of editors.

[37] The amendment would have penalized, with imprisonment for up to three years, anyone defaming Poland by accusing it of complicity in the Holocaust,[38] with exceptions for "freedom of research, discussion of history, and artistic activity".

[39][40] In July 2017, Grabowski criticized the Ulma-Family Museum of Poles Who Saved Jews in World War II, which opened in Markowa in 2016.

The garden will have plaques identifying the 1,500 towns in which the nearly 6,700 Poles lived who helped Jews and were recognized by Yad Vashem as Righteous Among the Nations.

[42] Grabowski co-wrote a Haaretz opinion piece in December 2018 criticizing Israeli historian Daniel Blatman, professor of modern Jewish history and Holocaust studies at the Hebrew University of Jerusalem, for accepting the post of chief historian at the newly formed Warsaw Ghetto Museum in Warsaw, Poland, and thus agreeing to be "the poster boy of [Polish] state authorities bent on turning back the clock and distorting the history of the Holocaust".

[44] Since publication of Hunt for the Jews, Grabowski has become subject to significant criticism in Poland, particularly from groups associated with Polish right-wing spectrum.

attempted to have him fired from his academic position, and he has faced harassment and death threats, leading to increased security patrols in his department at the University of Ottawa.

[48][49] In response, the Polish Center for Holocaust Research issued a statement of its own, entitled "In defence of Jan Grabowski's good name" — signed by seven of its members, including Barbara Engelking, Jacek Leociak and Dariusz Libionka, it called the criticism "as brutal as it is absurd".

[49] On 19 June 2017, about 180 historians of Holocaust and modern European history, including Christopher Browning, Mary Fulbrook, Deborah Lipstadt, Antony Polonsky, Dina Porat, Yitzhak Arad, and Robert Jan van Pelt, signed an open letter in Grabowski's defence, describing the campaign against Grabowski as "an attack on academic freedom and integrity", the letter emphasized that "[h]is scholarship [held] to the highest standards of academic research and publication", and that the PLPZ attempted to put forth a "distorted and whitewashed version of the history of Poland during the Holocaust era".

[48] In November 2018, Grabowski filed a defemation lawsuit in Warsaw against the PLPZ; he asked that each of their signatories buy a copy of Dalej jest noc and donate it to a Polish high school.