Local stories said it is named after a noted Subanen chieftain, "Dumi" and his wife, "Ingag". Another supposed origin of the name tells about the native fellow who was asked by a government agent as to what the name of the place was while watching a cockfight. After the game was over, the stranger inquired about the name of the place. The native curtly replied: "Duminag!" meaning "I won". The government agent misheard the word. Instead of "Duminag", he wrote down "Dumingag".
The authenticity of these stories, however, is questionable since there has never been a single piece of evidence or record that Dumi and Ingag had ever actually existed. The first non-Subanen settlers of Dumingag were from the Ilo-ilo town of Dumangas. According to more convincing sources, the earliest settlers arrived in Dumingag with renewed optimism after World War II and, starting their lives anew, they hailed the place as "Little Dumangas". Hence, this soon developed into the current name "Dumingag".
The town is bounded by the Province of Zamboanga del Norte on the western and northern side, Mahayag on the East, and the towns, Midsalip and Sominot on the South. It is the northernmost town in the province.