Karatsu (唐津市, Karatsu-shi) is a city located in Saga Prefecture on the island of Kyushu, Japan.

Its name, formed from the Japanese word roots 唐 kara (China, or continental East Asia in general), and 津 tsu (port), signifies its historical importance as an ancient trading port between Japan with China and Korea.

The northwest is a ria coast with many inlets and outlets, and due to its geographical features, this area has been a base for maritime traffic to the continent since ancient times.

The city also includes a number of populated offshore islands Fukuoka Prefecture Saga Prefecture Karatsu has a humid subtropical climate (Köppen Cfa) characterized by warm summers and cool winters with light to no snowfall.

Following the Meiji restoration, the town of Karatsu and the villages of Hamasaki, Irino, Kagami, Karatsu, Kirigo, Kitahata, Kuri, Kyūragi, Minato, Mitsushima, Nagoya, Nanayama, Ōchi, Ōmura, Onizuka, Sashi, Uchiage and Yobuko were established with the creation of the modern municipalities system.

On January 1, 2005, the towns of Chinzei, Hamatama, Hizen, Kyūragi, Ōchi, Yobuko and the village of Kitahata (all from Higashimatsuura District) were merged into Karatsu.

Karatsu has a mayor-council form of government with a directly elected mayor and a unicameral city council of 28 members.

In terms of national politics, the city is part of the Saga 2nd district of the lower house of the Diet of Japan.

The festival consists of 14 hikiyama (floats made of many layers of paper mache) being carried around the city's narrow streets to calls of "Enya!".

Regularly during Karatsu Kunchi, people in this town open their homes to friends and strangers to eat and drink; the primary focus is enjoying food, beer, and shochu, and having lively conversation.