Pinus taeda, commonly known as loblolly pine, is one of several subtropical pines native to the Southeastern United States, from East Texas to Florida, and north to southern New Jersey. The wood industry classifies the species as a southern yellow pine. U.S. Forest Service surveys found that loblolly pine is the second-most common species of tree in the United States, after red maple. For its timber, the pine species is regarded as the most commercially important tree in the Southeastern U.S. The common name loblolly is given because the pine species is found mostly in lowlands and swampy areas.

Loblolly pine is the first among over 100 species of Pinus to have its complete genome sequenced. As of March 2014, it was the organism having the largest sequenced genome size. Its genome, with 22 billion base pairs, is seven times larger than that of humans. As of 2018, assembly of the axolotl genome (32Gb) displaced loblolly pine as the largest assembled genome. The loblolly pine was selected as the official state tree of Arkansas in 1939.