The Coast redwood (Sequoia sempervirens) is the tallest tree species on earth.
This is a list of the tallest known tree species, as reflected by measurements of the tallest reliably-measured individual specimen. Although giant trees grow in both tropical and temperate regions, they are very restricted geographically and phylogenetically. All the known giant trees occur in mesic climates, and nearly all of them are found in three regions: western North America from California to British Columbia, Southeast Asia (especially Borneo) and southeastern Australia (especially Tasmania).

Two main opposing forces affect a tree's height; one pushes it upward while the other holds it down. By analyzing the interplay between these forces in coast redwoods (Sequoia sempervirens), a team of biologists led by George Koch of Northern Arizona University calculated the theoretical maximum tree height or the point at which opposing forces balance out and a tree stops growing. This point lies somewhere between 122 and 130 m (400 and 426 feet).[41] On the one hand, the researchers found, trees in forests "desire" to grow as tall as possible to overtake neighboring trees and reach stronger sunlight.