Oregano (US: , UK: ; Origanum vulgare) is a species of flowering plant in the mint family Lamiaceae. It was native to the Mediterranean region, but widely naturalised elsewhere in the temperate Northern Hemisphere.

Oregano is a woody perennial plant, growing 20–80 cm (8–31 in) tall, with opposite leaves 1–4 cm (1⁄2–1+1⁄2 in) long. The flowers which can be white, pink or light purple, are 3–4 mm (1⁄8–3⁄16 in) long, and produced in erect spikes in summer. It is sometimes called wild marjoram, and its close relative, O. majorana, is known as sweet marjoram. Both are widely used as culinary herbs, especially in Turkish, Greek, Spanish, Italian, Hispanic, and French cuisine. Oregano is also an ornamental plant, with numerous cultivars bred for varying leaf colour, flower colour and habit.