The ISA Brown is a crossbreed of chicken, with sex-linked coloration.

It is thought to have been the result of a complex series of crosses including but not limited to Rhode Island Reds and Rhode Island Whites, and contains genes from a wide range of breeds, the list of which is a closely guarded secret.

[2] ISA stands for Institut de Sélection Animale, the company which developed the crossbreed in 1978 for egg production as a battery hen.

In 2005, Institut de Sélection Animale (ISA) and Hendrix Poultry Breeders (HPB) merged in ISA B.V., which also became part of the multi-species breeding company, Hendrix Genetics.

In March 2005, Hubbard was purchased from Merial Ltd by Group Grimaud La Corbiere, SA.