Accusations that Israel has committed, or is in the process of committing, genocide against the Palestinian population of the Middle East are a familiar presence within anti- Israel and anti Zionist discourse. In the wake of the Hamas attacks of 7 October 2023 and the subsequent Israeli military invasion of Gaza, claims of an Israeli genocide reached new heights, culminating in Israel being accused of genocide by South Africa at the International Court of Justice. Such claims can be made directly or indirectly, via attempts to draw an equivalence between Auschwitz or the Warsaw Ghetto and the current situation in the Palestinian territories. This chapter examines the use of the concept of genocide in social media discussions responding to UK news reports about Israel in the years prior to the 2023 Israel- Hamas war, thereby setting out the pre-existing conditions for its rise to prominence in the response to that war. It provides a historical account of the development of the concept of genocide, showing its interrelation with antisemitism, the Holocaust and the State of Israel. It then shows how accusations of genocide started being made against Israel in the decades following the Holocaust, and argues that such use is often accompanied by analogies between Israel and Nazi Germany and forms of Holocaust distortion. The chapter then qualitatively analyses comments referencing a supposed Israeli genocide posted on the Facebook pages of major British newspapers regarding three Israel-related stories: the May 2021 escalation phase of the Arab- Israeli conflict; the July 2021 announcement that the US ice cream company Ben & Jerry’s would be boycotting Jewish settlements in the West Bank; and the rapid roll-out of the Covid-19 vaccine in Israel from December 2020 to January 2021.