Batticaloa (Tamil: மட்டக்களப்பு, Sinhala: මඩකලපුව) is a city (pop. 86,227 in 2012) in Northeastern Sri Lanka, known for its lagoon, historical landmarks and nearby beaches.

Batticaloa is the capital of the district of the same name. The town itself began on Puliyanthivu, an island in the lagoon, which is now linked to the mainland by three road bridges. This island contains the old town and many of the historical attractions. Today, Batticaloa is a regional trading hub, especially for rice and coconuts, which are the main crops in the area. This strategically-located town has been fought over many times, and was first captured the Portuguese in 1622. The Dutch took it in 1638, and were ousted by the British in 1796. The LTTE (Tamil separatists) controlled the area during the 1980s until it was retaken in 1991 by government troops. The area suffered immensely from the December 2004 tsunami.

The lagoon is famous for its "singing fish," supposed to be shell-fish which give forth musical notes. This phenomenon has been documented since the colonial era but the details remain hazy. Research into the phenomenon was suspended during the civil war, at first because the government was no longer in control of the area, and later when the lagoon was made off-limits after a nightly curfew. It is thought that a type of fish releases air from a swim-bladder, which creates different "songs". If you go on a tour of the lagoon late at night, the boatman will cut the motor and hand you an oar. you dip the oar in the water and press your ear to the handle end, and listen. Traditionally, local fishermen have navigated the lagoon at night by the different sounds they hear in the water.

Hinduism is the major religion of Batticaloa. Batticaloa has historically been a centre of Portuguese Burgher culture, supported in the modern era by the Catholic Burgher Union. In the 1980s, despite Burger emigration to Australia, the Union still numbered some 2,000 speakers of Sri Lankan Portuguese, making them the largest community still speaking the dialect. Now, only around 100 families still speak it, as the community has struggled to retain its identity and English and Sinhala have largely replaced the creole.

The old town is very compact, so is easily walkable. Tuk-tuks are available for, but agree on a price before departing. A rule of thumb is Rs. 100 per kilometre. Also, Sri Lankan Transport Board buses and private bus/van service are available.

• 7.71171581.7021391 Batticaloa Fort. This fort was built by the Portuguese in 1628 and was the first to be captured by the Dutch in 1638. Later, the fort was used by the British from 1745. It now contains government administration offices. 
• 7.71930681.7073332 Kallady Bridge. This bridge was built in 1924 during British colonial rule. The bridge was named Lady Manning Bridge in honour of the wife of William Manning, the British Governor of Ceylon. It was the oldest and longest iron bridge in Sri Lanka. 
• 7.75483581.6854453 Batticaloa Lighthouse. This lighthouse near the estuary in Palameenmadu was built in 1913 and is 28 metres high. It's around 5 km from Batticaloa city, on Bar Road. 

• 7.71375681.6983794 Gandhi Park & Batticaloa Gate. The Batticaloa Gate is a monument which was used as port to connect the town called Puliyanthivu (island) with the mainland of Batticaloa. This is believed to have been the landing site of Rev William Ault, who was the first Methodist missionary to Batticaloa, in 1814. Batticaloa Gate is a part of Gandhi Park. Within the closest area, public library and fountain park can be accessible. 
• 7.92467981.5659695 Pasikudah beach. This is a coastal resort town located about 35 km northwest of Batticaloa town. It is a popular tourist destination, especially for its calm water body and resorts & hotels 
• Heritage Museum. (updated Jul 2017)

• Hotels and travel agents can organise singing fish tours. Around Rs. 1500 pp, minimum 2, maximum 8 per boat. After 22:00, duration around 1 hour. The singing fish are best heard when skies are clear, although hearing them cannot be guaranteed.
• Swimming, especially at Pasikudah beach, which has calm water.
• Boat travel from Batticaloa lighthouse to Batticaloa Fort (about 3 km) is recommended.
• Bird watching with local guide. Seasonal & migrating birds visit the area. Kudumbimalai (literally "Hair-knot-rock") is a recommended place for bird watching.
• Watch the traditional folk dance kuthu being performed during Hindu festivals or other special events.

• Batticaloa shops have local souvenirs, which represent Batticaloa, with drawings of “singing fish” – a mythical image of a mermaid. Batticaloa known as “Land of Singing Fish”.
• Cargill Food City (1), 67, St. Anthony's Street, Batticaloa, ☏ +94 65 2227680, [email protected]. 
• Cargill Food City (2), No.03, Gnanasooriyam Square, Trinco Road, Batticaloa, ☏ +94 65 2228819, [email protected]. 

• Prawn, crab curd and cashew nuts are famous in Batticaloa. Seafood is common. Sri Lankan and Indian cuisines are available, including Western food at hotels.
• 7.71175781.6936581 RN Buffet & Take Away, 3rd Street Covington's Rd (Old Batti). Small place with authentic Italian food 
• Sunshine Bakery, 136,Trinco Road, ☏ +94 65 492 7927. Sri Lankan, Indian & Western food and snack 

• Tap water is mostly from wells, and its quality has declined as of 2020, mainly due to contamination by agricultural run-off. Stick to Bottled water. Coconut water is also common and beer and toddy are available.

On 21 April 2019 the Zion Church was targeted by militant Islamic suicide bombers. At least 28 people were reported dead.

• Arugam Bay, about 85 km south from Batticaloa, is a popular surfing and tourist destination. Two daily direct buses at 06:00 and 10:00. Rs.135, 5-6 hours. Stops for 1 hour in the town of Akuraivili. Tuk-tuks offer to take travellers directly from there to Arugam Bay for Rs.1500, but you could just wait for an hour for the bus to continue and not spend any additional money. The bus ride ends in town of Pottuvil, which is about 3-5 km to most guesthouses in Arugam Bay. Tuk-tuks ask for Rs.200-300, but Rs.150 is fair price. Or you could walk if no luggage; it's pleasant and flat.
• Pasikudah is a popular tourist destination, 35 km north, with beaches and flat year-round warm-water shallow-lagoons. There are inexpensive hotels and food.
• Polonnaruwa, west of Batticaloa, is an ancient capital city of Sri Lanka and listed as a UNESCO World Heritage site. It has ruins and bird- and elephant-watching places. Also, it connects with popular sites of Sigiriya and Dambulla.
• Trincomalee