UK banks and financial institutions examined in this report hold shares worth over £10.8 billion in companies that sell weapons, military equipment and technology to Israel and used to oppress Palestinians. Additionally, some of them facilitate loans to these companies... In June 2017, the Office of the United Nations High Commissioner for Human Rights (OHCHR) published guidance to the banking sector clarifying that banks and financial institutions have responsibilities under the UN Guiding Principles on Business and Human Rights to “avoid causing or contributing to adverse human rights impacts” and “to prevent or mitigate adverse human rights impacts that are directly linked to their operations, products or services by their business relationships”... Using evidence gathered from two financial databases... we investigated the relationship between some of the UK’s best known banks and financial institutions and a sample of 19 companies known to supply the Israeli military and the Israeli government with weapons and technology used in the oppression of Palestinians... Banks that hold shares in arms companies profit from the arms trade and lend legitimacy to the arms trade as a whole. By holding shares in companies that profit from Israel’s war crimes against the Palestinian people, UK banks and financial institutions are materially benefitting from those crimes and providing them with legitimacy...