The Africanized bee, also known as the Africanized honey bee and known colloquially as the "killer bee", is a hybrid of the western honey bee (Apis mellifera), produced originally by crossbreeding of the East African lowland honey bee (A. m. scutellata) with various European honey bee subspecies such as the Italian honey bee (A. m. ligustica) and the Iberian honey bee (A. m. iberiensis).

The East African lowland honey bee was first introduced to Brazil in 1956 in an effort to increase honey production, but 26 swarms escaped quarantine in 1957. Since then, the hybrid has spread throughout South America and arrived in North America in 1985. Hives were found in south Texas in the United States in 1990.

Africanized honey bees are typically much more defensive than other varieties of honey bees, and react to disturbances faster than European honey bees. They can chase a person a quarter of a mile (400 m); they have killed some 1,000 humans, with victims receiving 10 times more stings than from European honey bees. They have also killed horses and other animals.