Jolo, officially the Municipality of Jolo ([hoˈlo]; Tausug: Kawman sin Tiyanggi; Tagalog: Bayan ng Jolo; Chavacano: Municipalidad de Jolo), is a municipality and capital of the province of Sulu, Philippines. According to the 2024 census, it has a population of 152,067 people.

According to Dr. Najeeb M. Saleeby (1908) and in old maps such as the Velarde map, "Joló" was the historical Spanish spelling of the word "Sulu" that now refers to the province and the whole Sulu Archipelago, which the early Spaniards historically spelt as "Xoló", with the initial letter most likely formerly pronounced with the Early Modern Spanish [ʃ] sound, with [ʃoˈlo] the Spanish pronunciation of Sulu, but later evolved into the Modern Spanish [x], leading to its modern pronunciation [xoˈlo]. In many dialects, the initial sound is glottal, yielding [hoˈlo]. The Spanish version Joló is still used to pertain Sulu (both province, archipelago, and ancient sultanate) in Spanish writings. Meanwhile, the word "Sulu" itself comes from Tausug: Sulug, an older form of Tausug: Sūg, lit. 'sea current'.

In the 14th century, Arab traders landed on the island to introduce and convert its inhabitants to Islam. The native inhabitants on the island are the Tausūg people. The Tausugs are part of the larger Moro group which dominates the Sulu Archipelago. The Moro had an independent state known as the Sultanate of Sulu, which was politically and economically centered on Jolo, the residence for Sulu Sultanates. The Seat of the Royal Sultanate of Sulu was in Astana Putih, which is Tausug for ‘White Palace’ in Umbul Duwa in the municipality of Indanan on Jolo Island, later on, the capital was moved in Maimbung during the 1800s.

The Spanish failed to conquer and convert the Muslim areas in Mindanao. After colonising the islands in the north, they failed to take over the well-organized sultanates in the south.

The Sulu economy relied on the network of nearby trading partners. The Sultanate benefited from importing rice from northern Philippines, as the Sulu region had a chronic rice shortage. The Sultanate was unable to bring agriculture to its full potential because the area was prone to erratic rainfall and drought.

Since the 15th century, the Sulu Sultanate traded local produce with neighbors and with countries as far as China by sea. Most of the import and export trade was done with Singapore which was estimated to be worth half a million dollars annually. In 1870, the Tausug lost much of their redistributive trade to the Chinese because of the Spanish cruising system and Chinese immigration from Singapore. Mostly originating from the Fujian province, most of the Chinese in Jolo worked as craftsmen, skilled and unskilled laborers and domestic servants for wealthy Tausugs and Chinese. Singapore served as a training ground from which they learned the Malay language and became experienced in dealing with Southeast Asians. It was these Chinese who eventually dominated trade in Jolo and benefited greatly from Jolo's status as an entrepot, and exercised profound influence over the Sulu Sultanate. However, the Sultanate was not keen on the Chinese monopoly. By 1875, Sultan Jamal ul-Azam wanted an English merchant to establish himself in order to break the monopoly at Jolo.

Chinese who lived in Sulu ran guns across a Spanish blockade to supply the Moro Datus and Sultanates with weapons to fight the Spanish, who were engaging in a campaign to subjugate the Moro sultanates on Mindanao. A trade involving the Moros selling slaves and other goods in exchange for guns developed. The Chinese had entered the economy of the sultanate, taking control of nearly the entire Sultanate's economy in Mindanao and dominating the markets. Though the Sultans did not like their economic monopoly, they did business with them. The Chinese set up a trading network between Singapore, Zamboanga, Jolo and Sulu.

The Chinese sold small arms like Enfield and Spencer rifles to the Buayan Datu Uto. They were used to battle the Spanish invasion of Buayan. The Datu paid for the weapons in slaves. The population of Chinese in Mindanao in the 1880s was 1,000. The Chinese ran guns across a Spanish blockade to sell to Mindanao Moros. The purchases of these weapons were paid for by the Moros in slaves in addition to other goods. The main group of people selling guns were the Chinese in Sulu. The Chinese took control of the economy and used steamers to ship goods for exporting and importing. Opium, ivory, textiles, and crockery were among the other goods which the Chinese sold.