The Welsh Corgi ( or Corgi, plural Corgis, or occasionally the etymologically consistent Corgwn; ) is a small type of herding dog that originated in Wales. The name corgi is derived from the Welsh words cor and ci (which is mutated to gi), meaning "dwarf" and "dog", respectively.

Two separate breeds are recognized: the Pembroke Welsh Corgi and the Cardigan Welsh Corgi. Physical differences are seen between the two breeds. According to the breed standards, overall the Cardigan is larger, both in weight and height. Their tails are of different shapes, and docking was previously performed on Corgis before the practice was largely banned.

Historically, the Pembroke has been attributed to the influx of dogs alongside Flemish weavers from around the 10th century, while the Cardigan is attributed to the dogs brought with Norse settlers, in particular a common ancestor of the Swedish Vallhund.

The Pembroke is the more popular of the two, yet still appears on the Kennel Club's vulnerable dog breeds of the United Kingdom list. The Pembroke Welsh Corgi gained in popularity because Elizabeth II had personally owned more than 30 Pembrokes or Corgi-Dachshund crosses, known as dorgis.