According to a statement issued by the mission, the U.S. administration made the donation through the U.S. Agency for International Development (USAID) and the United Nations Development Program (UNDP).
The donation, it said, came as part of a pledge made by U.S. Secretary of State John Kerry at an October donor conference in Cairo devoted to rebuilding the war-battered strip.
At the conference, Kerry had pledged $414 million in additional U.S. assistance to the Palestinians.
Israel's 51-day onslaught, which ended on August 26, left more than 2,150 Gazans dead and 11,000 injured.
The offensive also partially or completely destroyed thousands of residential structures across the embattled enclave.
According to official Palestinian figures, a total of 15,671 housing units were damaged across the Gaza Strip, including 2,276 that were totally destroyed.
Launched with the stated aim of halting rocket fire from Gaza, the Israeli offensive finally ended on August 26 with an indefinite cease-fire celebrated by Palestinian resistance faction Hamas as a strategic victory.