The Pinta Island Galapagos tortoise is the largest living tortoise. The body length is 1.2 meters. The adult male tortoise is larger than the female. The adult male weighs about 272-320 kg, while the female is 136-180 kg. Pinta Island Galapagos tortoises are sexually dimorphic, with the most pronounced male and female in the shelled horseback type population, the male has more angles and a higher front opening, giving it a more extreme appearance . Male tortoises of all subspecies generally have longer tails with shorter concave thickened sides of the shell tails to facilitate mating.

Pinta Island Galapagos tortoises can be sexed at around 15 years of age, reach sexual maturity around 20-25 years, and reach full-sized standard size in the wild for 40 years. With a life expectancy of over 100 years in the wild, it is one of the longest-lived species in the animal kingdom. Harriet, the specimen kept at the Australian Zoo, is the oldest known Pinta Island Galapagos tortoise, estimated to be over 170 years old when she died in 2006.