The cockatiel is a small parrot of the Cacatuidae family. Like some other cockatoos, as for example the Sulphur-crested Cockatoo, the cockatiel has an erectible crest. Cockatiels and cockatoos in general also share other features, such as the facial feathers covering the sides of the beak, which are rarely - if ever - found outside the Cacatuidae family. In contrast to most cockatoos, the cockatiel has long tail feathers, roughly making up half of its total length. The cockatiel's distinctive pointed yellow crest is held erect when startled or excited, while a crest slightly tilted indicates a relaxed state of mind.

Female hand-raised cockatiel of typical coloring, age 15.The plumage is generally mid-grey, lighter underneath, with an orange cheek patch and a prominent white blaze on the wings. A row of yellowish spots can be found underneath the wings of female cockatiels, but not on the males. Some other mutations exist, such as the Lutino, which is a light yellow colour. Female Lutinos also have barred tail feathers. Both the cock and the hen have yellow facial feathers: the female has a yellow wash around the beak and eye, in the male, yellow covers most of the head and the fore part of the crest. Male cockatiels are very protective and nurturing of their offspring and are known to be very capable of raising their newborns if the mother is unable to.

Cockatiel lifespans in captivity are generally given as 15-20 years , though it is sometimes given as short as 12-15 years and there are anecdotes of cockatiels living as long as 30 years.