What breed of dog is Bluey?

Bluey is a Blue Heeler.

“Blue Heeler” is the familiar Australian name for a blue-coloured Australian Cattle Dog, the breed represented by Bluey Heeler in the series. Bluey is an anthropomorphic puppy whose blue, mottled appearance reflects the breed's characteristic coat colouring. The show's creator, Joe Brumm, chose a cattle dog to give the series an unmistakably Australian identity.

Australian Cattle Dogs were developed in nineteenth-century Australia to move cattle across long distances and difficult terrain. Their working heritage helps explain the breed's reputation for intelligence, stamina and high energy. The term “Heeler” refers to the dogs' traditional method of controlling cattle by nipping at their heels.

A frequent mistake is treating Blue Heeler and Red Heeler as separate breeds. They are colour-based names for Australian Cattle Dogs: blue and red are the two familiar coat forms. In the Heeler family, Bingo and Chilli are Red Heelers, while Bandit is also a Blue Heeler. Bluey's breed is therefore more precisely an Australian Cattle Dog, but “Blue Heeler” is the canonical answer used by the show.