Vedaranyam (Tamil: [ʋeːdaːɾaɳjam]) (also spelt as Vedaraniam and Vedaranniyam) is a municipality in Nagapattinam district in the Indian state of Tamil Nadu. The town is named after the presiding deity of the Vedaranyeswarar Temple. The recorded history of Vedaranyam is known from medieval Chola period of the 9th century and has been ruled, at different times, by the Medieval Cholas, Later Cholas, Later Pandyas, Vijayanagar Empire and the British. During India's independence struggle, C. Rajagopalachari, who would later become independent India's first Governor-General, launched a salt march in Vedaranyam parallel to the Dandi March launched by Gandhi in 1930 to protest against the sales tax levied on salt extraction.

Vedaranyam comes under the Vedaranyam assembly constituency which elects a member to the Tamil Nadu Legislative Assembly once every five years and it is a part of the Nagapattinam (Lok Sabha constituency) which elects its Member of Parliament (MP) once in five years. The town is administered by the Vedaranyam municipality, which covers an area of 36.26 km² (14.00 sq mi). As of 2011, the town had a population of 34,266. Vedaranyam was a part of Thanjavur District till 1991 and Nagapattinam District from then on. The town is a part of the fertile Cauvery delta region, but salt extraction and prawn cultivation are the major occupations. Roadways are the major mode of transportation to Vedaranyam and the nearest Airport is Tiruchirapalli Airport, located 135 km (84 mi) away from the town. On 17 November 2018, Vedaranyam was devastated by Cyclone Gaja.

Vetharanyam is named after Vedaranyeswarar, the presiding deity of the Vedaranyeswarar Temple, a Hindu temple dedicated to Shiva. The place was earlier known as "Tirumaraikadu", meaning the place where Vedas, oldest scriptures of Hinduism, originated. The 7th century Saiva canonical work Tevaram by Appar and Tirugnanasambandar mentions the place as "Tirumaraikadu". As per Hindu legend, the Vedas worshipped Shiva in this place, giving the name "Vedaranyam" to the place. According to another Hindu legend, Rama, the seventh avatar of god Vishnu, is believed to have visited Vedaranyam to absolve himself from sins committed in the war against the demon king Ravana. The footprints of Rama is preserved in a place called Ramar Padam near Vedaranyam. According to a Tamil legend, the Vedas locked the gates of the temple after worshipping Shiva. The Nayanmars (Saiva saints) Appar and Tirugnanasambandar could not enter the locked temple. At this, on Tirugnanasambandar's request, Appar sang devotional hymns praising Shiva, after which the gates opened. Tirugnanasambandar's devotional hymns locked the gates again.

The recorded history of Vedaranyam is found from the inscriptions in Vedaranyeswarar Temple. The inscriptions date from the reign of Aditya Chola (871–907), Rajaraja Chola I (985–1014), Rajendra Chola I (1012–1044) and Kulothunga Chola I (1070–1120) indicating various grants to the temple. Paranjothi Munivar, a 13th-century saint, who wrote the book Thiruvilaiyadal Puranam, was born at Vedaranyam.

Vedaranyam continued to be a part of the Chola Empire and the Chola region emerged as a centre of Saivism during the reign of Kulothunga Chola I (1070–1120). After the fall of Cholas during the reign of Rajendra Chola III in the 13th century, the erstwhile Chola region was caught under a power struggle between Pandyas and Hoysalas. The royal patronage continued to the temple during the rule of the Nayaks. The Negapatam region (modern day Nagapattinam district) was briefly captured by French troops led by Lally (1702–66) in 1759. The Tanjore district was annexed by British after the French failed to subdue the king of Tanjore. During the British period, Vedaranyam was part of Thiruthuraipoondi Taluk under Tanjore district. Salt from Vedaranyam was transported to Nagapttinam port through a 32 mi (51 km) long canal. The channel was constructed in 1869 because road transportation facilities between these two towns were limited.

During India's independence struggle, Gandhi launched the Dandi March along India's west coast to protest against the sales tax levied on salt extraction. His close associate C. Rajagopalachari, who would later become independent India's first Governor-General, carried out a salt march in parallel, on the east coast starting from Trichonopoly (modern day Tiruchirappalli) to Vedaranyam. His group, having people like Sardar Vedaratnam, started from Tiruchirappalli, in Madras Presidency (now part of Tamil Nadu), to the coast of the town. After making illegal salt there on 30 April 1930, the group was arrested by the British. After India's independence, Vedaranyam continued to be a part of Thanjavur district until 1991, and later became part of the newly created Nagapattinam district.

Vedaranyam has an average elevation of 1 m (3.3 ft) and is located on the Coramandel coast of Bay of Bengal. The Vedaranyam swamp is located parallel to the Palk Strait for 48 km (30 mi). The river Cauvery was flowing south easterly direction from Trichy and had its confluence at Vedaranyam due to the emergence of Vedaranyam nose (the nose shaped stretch from Vedaranyam to Kodiyakarai) during the pleistocene period. Due to the rise of tertiary rocks in the Pattukottai – Mannargudi region and also due to the increase of sediments in the Vedaranyam area, the river migrated northwards. There is lesser marine activity in the Vedaranyam shore due to the presence of Vedaranyam nose in the north and Sri Lanka in the south, both causing weak shore currents.

The quality of ground water is poor compared to the northern shores of Tamil Nadu due to the presence of marine and semi-marine origin in sediments. The images from the satellite IRS 1A shows Thiruthuraipoondi was a coastal town ^b (which is an inland in modern times) and the sea has regressed up to Vedaranyam in modern times. The analysis of backwaters from 1932 to 1992 indicates considerable enlargement in the region and occurrence of number of sand bodies.