The Kaffir lime (Citrus hystrix DC., Rutaceae) is a Southeast Asian citrus plant with very pungent leaves. The hourglass-shaped leaves are widely used in Thai cuisine.

Kaffir lime leaves are also popular in the west of Cambodia, but less so in Vietnam. Malay and Indonesian (especially, Balinese; see also Indonesian bay leaf) cuisines use them sporadically with chicken and fish.

The leaves can be used fresh or dried, and can be stored frozen. The juice and lime rinds can also be used but less often.

As for the zest, it is widely used in creole cuisine and to impart flavor to "arranged" rhums in the Reunion Island and Madagascar.

For other types of lime, see lime.