Pagadian, officially the City of Pagadian, is a component city and the capital of the province of Zamboanga del Sur, Philippines. It is the regional center of Zamboanga Peninsula and the second-largest city in the region, after the independent city of Zamboanga. According to the 2024 census, it has a population of 206,483 people. The city converted into a highly urbanized city by the virtue of Proclamation No. 1247, signed by President Rodrigo Duterte dated November 8, 2021.

Pagadian began as stop-over for traders who plied the road between the old Spanish fort-town of Zamboanga on the southwestern tip of the Zamboanga Peninsula and other bigger towns to the north of the old Zamboanga Province. Except for its sheltered bay and good fishing grounds, it was not a promising site because it is situated on steeply rolling terrain. In the course of its local history, waves of different kinds of people came to stay, and eventually called among themselves "Pagadianons".

The iconic symbol of Pagadian is its uniquely designed tricycle built to adopt to the city's hilly terrain. It is the only place in the Philippines with a public transport inclined at about 25-40° angle. In recent years, these iconic inclined public transport have been slowly being replaced by modernized tricycles that are locally called "bao-bao", a kind of auto rickshaw, due to the latter's fuel-efficiency, less noise and being environment-friendly due to its smoke-less emissions.

The name "Pagadian" originates from a Subanen corruption of the Iranun or Maguindanao term padian, meaning "marketplace" (compare with Parián). The modern city of Pagadian was founded on the sitio of Talapukan, which in turn meant "a place where springs abound."

The first known settlers in Pagadian were the Subanen people who established a coastal fishing and trading village. The settlers in what would later become Pagadian referred to themselves as "getaw Belengasa," or "from around the Balangasan River" to distinguish themselves from the nearby Subanen populations who were "getaw Dumenghilas" (from around the Dumangkilas River and Bay), "getaw Sibuguey" (from around the Sibuguey River and Bay), or "getaw Thebed" (from around the river of Thebed in Labangan).

In the early 17th century, the coastal regions of Zamboanga del Sur (including Pagadian) were annexed by the Sultanate of Maguindanao under Muhammad Kudarat, leading to an influx of Maguindanao and Iranun settlers.

Pagadian came under the local rule of Sultan Datu Akob, an Iranun datu whose daughter caught the fancy of Datu Macaumbang (Sultan of Taga Nonok), also an Iranun from Malabang, Tukuran that is now part of Pagadian. He was the son of Sharif Apo Tubo who descended from the bloodline of Sharif Kabungsuan, the first Sultan of the Maguindanao Sultanate. With the approval of Sultan Datu Akob, Datu Macaumbang married Bai Putri Panyawan Akob, the beautiful daughter of the Sultan of Pagadian and Royal Bai Putri of Raya.

Upon the death of Datu Akob also known as Datu Mimbalawag, his son-in-law, Datu Macaumbang (Sultan of Taga Nonok) assumed leadership; he established the territorial boundaries of the present city proper, from Balangasan River in the west of Tawagan Sur River in the east. Beyond the river of Tawagan Sur was the territory of Datu Balimbingan. At one time, Datu Macaumbang requested the assistance of the Philippine Constabulary due to the rampant banditry and piracy in the area. A detachment led by Col. Tiburcio Ballesteros stationed at Malangas landed at the place and stationed themselves at Dumagoc Island. The arrival of the soldiers restored peace and order, thereby attracting the influx of settlers from other places.