Najib will be accompanied by Foreign Minister Anifah Aman and other officials on the one-day visit on Tuesday, an aide to the prime minister told AFP on condition of anonymity.
The aide declined to give details of the visit or its purpose, saying an official statement would be issued on Monday.
Mainly Muslim Malaysia has long been a staunch supporter of the Palestinians' aspirations to statehood. It does not have diplomatic ties with Israel.
During the conflict in Gaza last November, Najib urged international powers to influence Israel to halt what he called its military aggression against the Palestinians.
The prime minister had said Malaysia was deeply concerned at the crisis and ready to help in any way possible. He urged Hamas, the Islamic movement which runs Gaza, to refrain from action that would cause the conflict to worsen.
A ceasefire between Israel and Hamas ended the November 14-21 fighting. The conflict left 177 Palestinians dead -- including about 100 civilians -- as well as six Israelis -- four civilians and two soldiers.
Qatar's Emir Sheikh Hamid bin Khalifa al-Thani made a landmark trip last October to Gaza, the first such visit by a head of state since Hamas took over the territory in 2007.