According to a statement released by OCHA, as of late Thursday, the figure had risen by 84,444 people to reach 423,378.
The UN agency said that two thirds of the displaced are taking refuge in schools of the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA).
Israeli forces have launched a sustained and forceful military campaign against the Gaza Strip in response to a military offensive by the Palestinian group Hamas in Israeli territories.
The conflict began when Hamas initiated Operation Al-Aqsa Flood, a multi-pronged surprise attack that included a barrage of rocket launches and infiltrations into Israel via land, sea and air.
Hamas said the attack was in retaliation for the storming of Al-Aqsa Mosque in occupied East Jerusalem and Israeli settlers’ growing violence against Palestinians.
In response, the Israeli military launched Operation Swords of Iron against Hamas targets within the Gaza Strip.
That has extended to cutting water and electricity supplies to Gaza, further worsening living conditions in an area that has reeled under a crippling siege since 2007.