It had been closed to humanitarian shipments on Sunday following a rocket attack by the Palestinian Islamist organisation Hamas.
Despite another rocket attack from the Gaza Strip on Tuesday, lorries from Egypt with humanitarian aid, including food, water, equipment for shelters, medicines, and medical supplies donated by the international community, have now arrived at the crossing, the Israeli army said.
After a thorough security inspection, the equipment will be transported to Gaza. However, the number of lorries involved was not specified.
Aid supplies are also entering Gaza via the Erez checkpoint in the north.
Israel's Western partners, including Germany, had urged the government in Jerusalem to reopen the crossing given the catastrophic humanitarian situation for civilians in the Gaza Strip.
The Palestinian Territory has been the target of a massive Israeli air and ground offensive since the October 7 terrorist attacks led by Hamas in southern Israel.
The Rafah crossing on the border with Egypt is another crucial crossing point, but the situation there is unclear after the Israeli army took control of the Palestinian side of the crossing on Monday night.