In clothing for men, a dickey (also dickie and dicky, and tuxedo front in the U.S.) is a type of shirtfront that is worn with black tie (tuxedo) and with white tie evening clothes. The dickey is usually attached to the shirt collar and then tucked into the waistcoat or cummerbund. Some dickey designs have a trouser-button tab, meant to secure the dickey-bottom to the waistband of the trousers, and so prevent the dickey from becoming untucked.

Originally called the detachable bosom, the dickey shirtfront, made of rigid plastic, was the fashion in shirts in the late 19th century; the dickey also was one of the first successful, commercial applications of celluloid. Like the detachable shirt collar, the dickey (a bosom-front for a dress shirt) was invented as a separate accessory for the shirt, which thus could be washed, starched, and pressed more readily than could be laundered if the dickey were an integral part of the shirt.

Among dandies, the use of a dickey is considered bad style in the wearing of traditional modes of black tie and white tie evening dress. Etymologically, the word "dickey" is from Cockney rhyming slang, wherein dicky dirt denotes a shirt. In 1850s Britain, office workers wore business suits, yet their low wages disallowed a work week's supply of laundered shirts, so they adopted the dickey as a practical extension of the sartorial life of a dress shirt at work.