Which breed is the smallest in size among all dog breeds?

The Chihuahua is the smallest recognized dog breed in the world.

This Mexican toy breed is known for its compact body, large erect ears, and rounded “apple-dome” skull. Breed standards emphasize weight and overall proportion rather than a fixed height; show Chihuahuas generally weigh no more than about 5.9 pounds under the American Kennel Club standard.

The breed’s history reaches back to Mexico. Genetic studies suggest that modern Chihuahuas retain a small amount of ancestry from pre-Columbian Indigenous American dogs, unlike most modern breeds, which are primarily descended from European lineages. The American Kennel Club registered its first Chihuahua in 1904.

A common mix-up is confusing the smallest breed with the smallest individual dog. Record-holding dogs, including Miracle Milly and Pearl, have also been Chihuahuas, but individual records can change and do not define the breed’s standard size. “Teacup Chihuahua” is not a separate officially recognized breed variety.