Cassida is a large Old World genus of tortoise beetles in the subfamily Cassidinae.

The natural history of Cassida sphaerula in South Africa is a typical life cycle.

[1] Several species of Cassida are important agricultural pests,[2] in particular C. vittata and C. nebulosa on sugar beet and spinach.

The genus name is derived from Latin Cassis for a metal helmet.

[5] Larvae build shields with their feces and exuviae, a widespread pattern of tortoise beetles.