The reason for his visit to the embattled Palestinian territory were not initially disclosed.
According to Israeli media, he was visiting Israeli soldiers there.
Netanyahu has previously entered the Gaza Strip a handful of times during the war.
He last visited the blockaded coastal strip in July.
At that time he also paid an unannounced visit to Israeli soldiers in the southern Gaza Strip.
The visit comes as Israel's longest-serving prime minister faces duelling, possibly incompatible pressures: families of the Israeli hostages want him to cut a deal with Hamas to free them while his coalition partners want to continue the war with the aim of annihilating the militant group.
Israeli troops are currently working to expand a so-called "security zone" in the north of the Gaza Strip.
Defence Minister Israel Katz is threatening to permanently occupy parts of the Gaza Strip.
According to the Israeli government, this is also intended to increase pressure on the Palestinian Islamist Hamas movement to release the remaining hostages.
The trigger for the Gaza Strip war was an unprecedented massacre carried out by Hamas and other militants on October 7, 2023, in southern Israel.
Israeli officials say that their offensive will continue until the remaining 59 hostages are freed and the Gaza Strip is demilitarised.
Hamas insists it will free hostages only as part of a deal to end the war and has rejected demands to lay down its arms.
with AP and DPA
