Jagna appears in documents as early as March 15, 1565 when Miguel Lopez de Legaspi was driven by unfavorable winds towards this coast and because his flagship "San Pedro" underwent repairs along Jagna bay.
The Society of Jesus (Jesuits) started their work in what was known as San Miguel de Hagna as early as 1596. The Recollect historian Licinio Ruiz wrote that the Jesuit priest P. Jose Sanchez founded the parish and town simultaneously on September 29, 1631 with St. Michael Archangel as its patron saint.
The name Jagna was, according to historical records, derived from legendary vernacular exclamation "ni hagna na". The tale started from the usual occurrence at the mouth of a small river which is already dried up now but whose actual traces of real existence are still visible beyond doubt. At the mouth of the river was a hole or cave-in of considerable depth and size. Such condition of the river led the early inhabitants to call it as "Boho River". The river used to abound with so much fish called "tigue" in the local dialect. When the school of that particular fish played on the surface of the water, such part seemed to appear like coconut oil boiling in a frying pan. And whenever the people saw the sizzling surface of the water caused by the movement of the fish, they used to remark "ni hagna na", meaning the oil being cooked is almost done. Therefore, from this common expression of the villagers evolved the present name of the town "JAGNA".
The first settlers of Jagna descended from the natives of Loboc and Talibon. These settlers wanted to migrate to Mindanao riding on their sailboats called "bilos". Because of the inclement weather, they were forced to seek shelter in Jagna. However this brief refuge turned into a permanent stay as they found Jagna attractive and an ideal place for establishing a village.