Koi (Lao: ກ້ອຍ; Thai: ก้อย, Thai pronunciation: [kɔ̂j]) is a "salad"[clarification needed] dish of the Lao people living in modern-day Laos Isan, Thailand and Thai people of Vietnam (Son La province) consisting of raw meat denatured by acidity, usually from lime juice.

Common varieties include koi kung (Thai: ก้อยกุ้ง), with shrimp as the main ingredient, and koi paa (Lao: ກ້ອຍປາ)/koi pla (Thai: ก้อยปลา), which consists of minced or finely chopped raw fish in spicy salad dressing.

Koi made with raw fish is a popular dish in Laos and Isaan and a common source of infection with the Southeast Asian liver fluke Opisthorchis viverrini.

[1] Koi pla eaten in north-east Thailand is made from raw fish, live red ants, herbs and lime juice.

[2] Koi pla is eaten soon after it is prepared, without a long period of soaking in acid juice.