It is migratory, ranging from mid-Alberta to North Carolina during the breeding season, and from just south of the Canada–United States border to Mexico during the winter.

The American goldfinch was one of the many species originally described by Carl Linnaeus in the landmark 1758 10th edition of his work, Systema Naturae, where he classified it in the genus Fringilla.

[11] The beak is small, conical, and pink for most of the year, but turns bright orange with the spring molt in both sexes.

[13] The markings on these feathers remain through each molt, with bars on the wings and white under and at the edges of the short, notched tail.

[13] Once the spring molt is complete, the body of the male is a brilliant lemon yellow, a color produced by carotenoid pigments from plant materials in its diet,[15] with a striking jet black cap and white rump that is visible during flight.

[14] After the autumn molt, the bright summer feathers are replaced by duller plumage, becoming buff below and olive-brown above, with a pale yellow face and bib.

[18] The American goldfinch prefers open country where weeds thrive, such as fields, meadows, flood plains, as well as roadsides, orchards, and gardens.

[12] The American goldfinch is a short-distance migrant, moving south in response to colder weather and lessened food supply.

[21] Its winter range includes southern Canada and stretches south through the United States to parts of Mexico.

In southern ranges, during winter, they remain in areas like fields and flood plains where they live during the summer months.

[22] Attempts were made to introduce the American goldfinch into Bermuda in the 19th century and Tahiti in 1938, but the species failed to become established in either place.

[26] The American goldfinch is gregarious during the nonbreeding season when it is often found in large flocks, usually with other finches.

[27] The social hierarchy, measured by how many aggressive encounters are won by each individual, tends towards the male being dominant in the nonbreeding season.

The head-up display, where the neck and legs are slightly extended, shows mild aggression and is often performed by the victor of an encounter.

In extreme cases, the neck is retracted, the bill opened, the body feathers sleeked, and the tail is fanned and raised slightly.

Avoidance behaviors include showing only the side of the body to an aggressor, leaning away, and flexing the legs, retracting the neck, and pointing the beak down.

[28] The breeding season begins later in the year than for any other finch and later than any other native North American bird, besides occasionally the sedge wren.

[13] The nest is built in late summer by the female in the branches of a deciduous shrub or tree at a height of up to 10 m (33 ft).

[19] The rim is reinforced with bark bound by spiderwebs and caterpillar silk, and the cup is lined with plant down from milkweed, thistle, or cattail.

[22] The eggs are incubated by the female alone, though the male brings her food as she nests, and most mating pairs raise only one brood each year.

Like all passerines, the chicks are altricial; they are hatched naked, with reddish bodies, pale grey down, and closed eyes.

[33] The American goldfinch also makes a very poor host for brood parasites, with studies showing low hatching rates of brown-headed cowbird eggs and no fledging success.

Its diet consists of the seeds from a wide variety of plants, often those of weeds, grasses, and trees, such as thistle, teasel, dandelion, ragweed, mullein, cosmos, goatsbeard, sunflower, and alder.

This dexterity enables it to take advantage of food sources relatively inaccessible to potential competitors, increasing its chances of survival.

[13] The American goldfinch has a large range, with an estimated global extent of about 11,300,000 km2 (4,400,000 sq mi) and an increasing population.