Dinalungan is a 5th class municipality in the province of Aurora, Philippines. According to the latest census, it has a population of 10,145 people in 1,875 households.

Formerly a barrio of Casiguran, the municipality of Dinalungan was created in 1966. It is bounded on the north by the Dinalungan River, on the south by the Dinadiawan Creek, on the west by the provinces of Quezon and Nueva Vizcaya, and on the east by Casiguran Sound.

In 1942, the occupied by the Japanese forces landed in then town of Dinalungan, Tayabas.
In 1945, entering to the Philippine Commonwealth troops of the 3rd, 5th, 51st, 52nd, 53rd, 55th, 56th and 57th Infantry Division of the Philippine Army was liberated in the town of Dinalungan in the battles against the Japanese troops started in the Siege of Dinalungan in the Second World War.

Dinalungan is the least populous municipality in Aurora. It is bound by the Dinalungan River, Dinadiawan Creek and Casiguran Sound. While surrounded by water, the town is nestled in the mountains, making for excellent hikes that afford spectacular views of the ocean.