Papaver somniferum, the opium poppy, is a species of flowering plant in the family Papaveraceae. It is the species of plant from which opium and poppy seeds are derived and is a valuable ornamental plant, grown in gardens. Its native range is probably the eastern Mediterranean, but is now obscured by ancient introductions and cultivation.

The opium poppy is the only species of Papaveraceae that is grown as an agricultural crop on a large scale. Other poppy species, such as Papaver rhoeas and Papaver argemone, are important agricultural weeds, and may be mistaken for the crop.