The American mink has a long body, which allows the species to enter the burrows of prey and streamlined shape helps it to reduce water resistance whilst swimming. A chocolate brown with some irregular white patches on the chin, throat, and belly. White patches are usually larger on females and often occur on the abdomen in the area of the mammary glands. Adult males range in total length from 19 to 29 inches. They may weigh from three to almost five pounds. Their movements are rapid and erratic as if they are always ready to either flee or pounce on an unwary victim.

This species is typically associated with water, and is found near streams, rivers, lakes, swamps, and marshes, and also along coastlines. However, they also inhabit drier areas that are not close to the water and sometimes even urban areas, depending on the abundance of food. American minks prefer habitats where there is dense vegetation, as this provides plenty of cover. The American mink is a carnivore that feeds on rodents, fish, crustaceans, frogs, and birds. It is the animal most frequently farmed for its fur in economic importance.