Jaljulia (Arabic: جلجولية, Hebrew: גַ׳לְג׳וּלְיָה), officially also spelled Jaljulye, is an Arab town in Israel near Kfar Saba. In 2023 it had a population of 10,754.

An archaeological dig started in 2017 at Jaljulia uncovered, at about a five-meter depth, a half-million-year-old "paradise" for Homo erectus hunter-gatherers, including hundreds of knapped flint hand-axes. According to the Israel Antiquities Authority, recurrent occupation of the site indicates that prehistoric humans possessed a geographic memory of the place and could have returned here as a part of a seasonal cycle.

In Roman times the village was known as Galgulis, while during the Crusader period it was referred to as Jorgilia in 1241 C.E. It has been suggested that a Crusader sugar factory was later turned into an Ottoman mosque.

In 1265 C.E. (663 H) Sultan Baybars allocated equal shares of the village to three of his amirs. One of these, amir Badr al-Din Baktash al-Fakri, included his section of the village in a waqf he established. Excavations of a building close to the Mamluk khan yielded ceramics dating from that period.

The mosque is locally known as Jami' Abu´l-Awn, which associates it with the 15th-century religious leader Shams al-Din Abu´l-Awn Muhammad al-Ghazzi, who is known to have come from the town. The architecture of the mosque is, according to Petersen, consistent with a 15th or early 16th century construction date. At present the structure consists of one large vaulted chamber, and three small barrel-vaulted cells. A large second chamber to the west was destroyed by British artillery during World War I.

The khan is opposite the mosque. It was built by Sayf al-Din Tankiz, the governor of Damascus 1312–1340, and it was still functioning in the 16th century, when it was mentioned in an Ottoman firman. In the 19th century it was seen by Guérin, who described it as a beautiful khan with a (ruined) polygonal minaret. Petersen, who surveyed the structure in 1996, found the courtyard entirely overgrown and it was not possible to detect any features within; however, he notes that a 19th-century visitor had mentioned that there was "a great round well" in the centre.

In 1517, the village was included in the Ottoman Empire with the rest of Palestine, and in the 1596 tax-records it appeared located in the nahiya (subdistrict) of Banu Sa´b, part of Sanjak of Nablus, with a population of 100 households ("Khana"), all Muslim. The villagers paid taxes on a number of crops, including wheat and barley, as well as "summer crops", "occasional revenues", "goats and bees", and a market toll. There was also a poll tax, jizya, paid by all the inhabitants in the Sanjak of Nablus. Total taxes were 18,450 akçe, of which 1/6 went to a waqf.

Jaljulia appeared under the name of Gelgeli on Jacotin's map drawn-up during Napoleon's invasion in 1799.