A foot fetish is a sexual interest in feet. In other words, feet, toes, and ankles turn you on. This particular preference for feet can vary from person to person.

Some people are turned on just by looking at feet. Others may find painted nails, jewelry, or other adornments appealing.

Still others get sexual satisfaction in foot treatments, such as massaging or worshiping feet.

Foot fetishism has been defined as a pronounced sexual interest in feet.
For a foot fetishist, points of attraction may include the shape and size of feet, feet soles, toes, jewelry (e.g., toe rings, anklets, etc.), treatments (such as massaging, washing partner’s feet or painting partner’s toenails), state of dress (barefoot, flip flops, ballet flats, sandals, high heels,[4] hosiery, socked feet, etc.), foot odor or sensory interaction (e.g., rubbing the foot, tickling, licking, rubbing genitals on foot, etc.).[5]

Extensions of this fetish include shoes, socks, olfactophilia (odor fetishism) and tickling. Cited from Wikipedia