Aparri is a 1st class municipality in the province of Cagayan, Luzon, Philippines. According to the latest census, Aparri has a population of 69,024 people.

Aparri has an approximate income of Php 90,000,000.00. Aparri sits at the mouth of the Cagayan River, the longest river in the Philippines, about 55 miles north of Tuguegarao, the provincial capital.

Aparri was then a Japanese trading post established on 1405 because of its location at the northern tip of Luzon. But it was established as one of the major ports of the Galleon Trade on May 11, 1680 because it is located at the mouth of the mighty Cagayan River towards the flourishing city of then Nueva Segovia. The original inhabitants of this town were the Ybanags/Ibanags. Later, as the Spaniards settled and with its strategic location, Ilocanos and Chinese people settled in the area.

The valley is one of the largest tobacco-producing sections in the Philippines; and the town has a considerable coastwise trade.

It has a meteorological station located at Punta where the Cagayan River meets the Babuyan Channel.