It breeds on the Pacific coast of southern California in the United States and western Mexico, and migrates south to Peru, Ecuador and Chile for the northern winter; in the late summer and fall, some also disperse north to Oregon and more rarely Washington.

This species breeds in very dense colonies on coasts and islands, including Isla Rasa[2] and Montague Island in Mexico,[3] and South Bay Salt Works (San Diego) and Bolsa Chica Ecological Reserve in California.

The current genus name is derived from Greek Thalassa, "sea", and elegans is Latin for "elegant, fine".

[9] Though described in 1822, the genus was largely treated as a synonym of Sterna until a 2005 study demonstrated that the systematics of the terns needed review.

[11][12][13] This is a medium-large tern, with a long, slender, slightly downcurved orange bill, pale gray upperparts and white underparts.

This species is marginally paler above than the lesser crested tern with a white (not gray) rump, with a slightly longer, more slender bill with a different curve.