Orthalicus reses, the Stock Island tree snail, is a species of large tropical air-breathing tree snail, a terrestrial pulmonate gastropod mollusk in the family Orthalicidae. It was first described in 1830 by the American naturalist Thomas Say. The holotype, a specimen probably collected in Key West, was subsequently lost. Over a hundred years later, in 1946, the American biologist Henry Augustus Pilsbry redescribed the species using a specimen from Stock Island, Florida. Orthalicus reses has two subspecies, O. reses reses and O. reses nosodryas. The validity of these two taxa is still being discussed, but some experts argue that considering them as independent units may be important for management purposes.

Orthalicus is a genus of land snails in the family Orthalicidae.