The Scottish Terrier (Scottish Gaelic: Abhag Albannach; also known as the Aberdeen Terrier), popularly called the Scottie, is a breed of dog. Initially one of the highland breeds of terrier that were grouped under the name of Skye Terrier, it is one of five breeds of terrier that originated in Scotland, the other four being the modern Skye, Cairn, Dandie Dinmont, and West Highland White terriers. They are an independent and rugged breed with a wiry outer coat and a soft dense undercoat. The First Earl of Dumbarton nicknamed the breed "the diehard". According to legend, the Earl of Dumbarton gave this nickname because of the Scottish Terriers' bravery, and Scotties were also the inspiration for the name of his regiment, The Royal Scots, Dumbarton’s Diehard. Scottish Terriers, were originally bred to hunt vermin on farms.

They are a small breed of terrier with a distinctive shape and have had many roles in popular culture. They have been owned by a variety of celebrities, including the 32nd president of the United States, Franklin Delano Roosevelt, whose Scottie Fala is included with FDR in a statue in Washington, D.C., as well as by the 43rd president, George W. Bush. They are also well known for being a playing piece in the board game Monopoly. Described as territorial, feisty dogs, they can make a good watchdog and tend to be very loyal to their family. Healthwise, Scottish Terriers can be more prone to bleeding disorders, joint disorders, autoimmune diseases, allergies, and cancer than some other breeds of dog, and there is a condition named after the breed called Scotty cramp. They are also one of the more successful dog breeds at the Westminster Kennel Club Dog Show with a best in show in 2010.