|Species||Aldabra giant tortoise|
|Died||22 March 2006 (aged 255–256)|
Alipore Zoological Gardens, Kolkata, India
|Known for||Believed to be the oldest terrestrial animal in the world, if verified.|
|Weight||250 kg (551 lb)|
Adwaita (from अद्वैत, meaning "one and only" in Sanskrit) (c. 1750 – 22 March 2006), also spelled Addwaita, 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.
He may have been from Aldabra, an atoll in the Seychelles. This anecdotal report has not been confirmed. The animal was one of four tortoises that lived at Robert Clive's estate at Barrackpore, in the northern suburbs of Calcutta. Clive was said to have received the tortoises following his victory at the Battle of Plassey in 1757, in which the British East India Company defeated the Nawab of Bengal and his French allies, thereby securing India for Britain in the long run. Adwaita was transferred to the Alipore Zoo in Calcutta 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 at an estimated age of 255.
Weighing 250 kg (551 lb), Adwaita was a solitary animal with no records of his progeny. He lived on a diet of wheat bran, carrots, lettuce, soaked gram (chickpea), bread, grass and salt.
His shell cracked in late 2005, and a wound developed in the flesh underneath the crack. The wound became infected and eventually led to his death from liver failure on 22 March 2006. Adwaita is estimated to have been at least 255 years old. If this latter estimate can be confirmed, Adwaita will have been the oldest known tortoise of modern times, living longer than Harriet by 80 years, Tu'i Malila by 67 years and Jonathan by 65 years.
- Encyclopedia of Life (2014). "Aldabra Tortoise (Geochelone gigantean)". Encyclopedia of Life. Retrieved 28 January 2014.
- BBC News – South Asia (23 March 2006). "'Clive of India's' tortoise dies". BBC News. BBC Online. Retrieved 23 January 2014.
- Lal, Vinay (April 2006). "Clive and his Pet Tortoise". MANAS, UCLA Social Sciences. Retrieved 16 June 2020.
- "Zoological Garden". Proceedings of the Asiatic Society of Bengal: 23–24. February 1876.