A sock fetish is a sexual interest in socks. This includes attraction to and arousal by the wearing of socks and their sexualized removal. A sock fetish appears to be related to foot fetishism, only the feet these fetishists admire are wearing socks. It is usually women's socked feet that are fetishized.
Online, sock fetishists might view pictures of socked feet, or even purchase worn socks to smell and enjoy in the privacy of their homes. In this way, sock fetishism resembles a used panty fetish, for which there is a sizeable online market.
The smelling of used clothing items, and the fetishes that fall within that realm, may also be referred to as olfactophilia, or an arousal that is derived from particular odors. In the case of a sock fetishist, that odor is dirty socks. A 1994 study found that 45% of people with foot fetishes are aroused by smelly used socks.