The dog’s full name is Caitland Isle Take a Chance and was named best-in-show at the 115th Crufts beating 22,000 other canines from 32 countries.
The five-year-old dog also took the top title in the pastoral group to make it to the final.
Owner, Californian Nancy Resetar, said the five-year-old Canadian-bred champion was the first Australian Shepherd she had shown.
Winning handler Larry Fenner said: "I am overwhelmed. The greatest moment of my life was the birth of my daughter, this is second best. I did not expect it."
Judge Brenda Banbury said: "We had excellent dogs sent through. Some moved very well, others were not quite so settled, but all were excellent dogs."
Crufts was established in 1891, and runs for four days in March. The best-in-show award is renowned as the pinnacle of any dog and owner's career.