Adwaita (meaning "unique" in Sanskrit) (c. 1750 – 22 March 2006) (aged about 255) was a male Aldabra giant tortoise that lived in the Alipore Zoological Gardens of Kolkata, India. At the time of his death in 2006, Adwaita was believed to be amongst the longest-living animals in the world.
Adwaita was reportedly given to Robert Clive (1725–1774) of the East India Company by British seafarers who captured it from Aldabra, an atoll in the Seychelles. This anecdotal report has not been confirmed. The animal was one of four tortoises that resided at Clive's estate at Barrackpore, in the northern suburbs of Kolkata. Adwaita was transferred to the Alipore Zoo in 1875 or 1876 by Carl Louis Schwendler, the founder of the zoo. Adwaita lived in his enclosure in the zoo until his death on 22 March 2006.
Weighing 250 kg (590 lb), Adwaita was a solitary animal with no records of his progeny. He lived on a diet of wheat bran, carrots, lettuce, soaked gram, bread, grass and salt.
His shell cracked in late 2005, and a wound developed in the flesh underneath the crack. The wound became infected, which eventually led to his death from liver failure on 22 March 2006. Adwaita is estimated to have been at least 150 years old at the time of his death. Some estimates suggest the animal may have been at least 250 years old at the time of his death. If this latter estimate can be confirmed, Adwaita would have been the oldest known tortoise of modern times, living longer than Harriet by 80 years, and Tu'i Malila by 67 years.
- Encyclopedia of Life (2014). "Aldabra Tortoise (Geochelone gigantean)". Encyclopedia of Life. Retrieved 2014-01-28.
- BBC News – South Asia (2006-03-23). "'Clive of India's' tortoise dies". BBC News (BBC Online). Retrieved 2014-01-23.
- "Zoological Garden". Proceedings of the Asiatic Society of Bengal: 23–24. February 1876.
- "Kolkata toasts 255-year-old resident". May 6, 2005.