Kalmunai has a historical background that dates back centuries. The region has been influenced by various civilisations, including the ancient Tamil kingdoms, colonial powers, and the indigenous Muslim community. Over time, Kalmunai became an important trading post due to its coastal location, facilitating maritime trade routes with other countries.

During the Sri Lankan civil war, Kalmunai experienced the devastating effects of the conflict. The city faced numerous challenges, including forced disappearances, civil unrest, and violence targeted at local civilians.

In 2004, Kalmunai was severely impacted by the Indian Ocean tsunami. The natural disaster resulted in the loss of many lives and caused extensive damage to the city’s infrastructure and property.

Kalmunai is governed by a system of administrative divisions that reflect the diverse characteristics and neighborhoods within the city. The main divisions of Kalmunai include.

• Kalmunai Central: This division encompasses Kalmunai Town, Kalmunai Kudy, Natpaddimunai, and Chenaikudiruppu. Kalmunai Town serves as the primary commercial and administrative center of the city, catering to various needs of the residents.
• Sainthamaruthu: Located in the southern part of Kalmunai, Sainthamaruthu is a prominent residential area with its own distinct community and cultural activities. It has its separate division to ensure effective governance and administration.
• Pandiruppu: Situated in the eastern part of the city, Pandiruppu functions as a separate administrative division within Kalmunai.
• Maruthamunai: Maruthamunai is a neighborhood in Kalmunai, offering a range of amenities and services to its residents. It is part of the larger administrative framework of the city.
• Periyaneelavanai: This village is located to the north of Kalmunai and acts as a border between Ampara and Batticaloa Districts.

In addition to these divisions based on geographical locations, Kalmunai also has administrative divisions that cater to specific communities.

• Kalmunai Muslim Division: This division, primarily centered around Kalmunai Central, is dedicated to serving the Muslim community residing in the city. It focuses on addressing the specific needs and concerns of the Muslim population.
• Kalmunai Tamil Division: The Tamil Division is responsible for governing the northern part of Kalmunai, primarily inhabited by Tamil Hindus. It ensures the provision of services and facilities tailored to the requirements of the Tamil-speaking population.
• Sainthamaruthu Division: As a separate division within Kalmunai, Sainthamaruthu is dedicated to addressing the administrative needs of the residents in the southern part of the city, emphasizing the unique characteristics and requirements of the area.