A deerstalker is a type of hat that is typically worn in rural areas, often for hunting. Because the hat's popular association with Sherlock Holmes, it is also a stereotypical hat of a detective.

Its main feature is the set of four flexible brim flaps that are position back, forth and the sides of the hat. They can be adjusted up or down to suit the needs of the wearer depending on the weather. The most common arrangement is the front and back flaps being down while the side ones are folded up and tied into place.

The most famous wearer of this kind of hat is the fictional character Sherlock Holmes, who is typically depicted favoring this hat. However, uninformed depictions which have Holmes wearing this hat in the city fail to realize that the fashion conscious Holmes in the original stories would never do that. This is because this kind of hat was restricted to the country and was considered a fashion faux pas to wear one in an urban setting. It would be the modern day equivalent of wearing hunting orange clothes as casual wear in an urban area which is generally considered inappropriately out of place.