The sweet pea, Lathyrus odoratus, is a flowering plant in the genus Lathyrus in the family Fabaceae (legumes), native to Sicily, southern Italy and the Aegean Islands.

It is an annual climbing plant, growing to a height of 1–2 metres (3 ft 3 in – 6 ft 7 in), where suitable support is available. The leaves are pinnate with two leaflets and a terminal tendril, which twines around supporting plants and structures, helping the sweet pea to climb. In the wild plant the flowers are purple, 2–3.5 cm (3⁄4–1+1⁄2 in) broad; they are larger and highly variable in color in the many cultivars. Flowers are usually strongly scented.

The annual species, L. odoratus, may be confused with the everlasting pea, L. latifolius, a perennial.