The Yellow Canary's length averages 10 cm. In the northwest, the adult male is almost entirely yellow, while in the southeast, the bird has an olive back with streaks. Its underparts, rump, and tail sides are also yellow. The female has grey-brown upperparts, black wings with yellow flight feathers, and a pale supercilium. The underparts are white with brown streaks. The juvenile is similar in appearance to the female, but with more pronounced streaking.