A merry widow is a women's foundation garment which is intended to smooth the waist and stomach area while also pushing up the bust. It is one of a number of garments designed for this purpose. Such supportive garments have largely fallen out of fashion for daily wear, but they are used on formal occasions or as dressy lingerie. Many lingerie stores carry a selection of merry widows, which women should try on if they are thinking of purchasing one, to ensure that the fit is comfortable and that the garment looks good.

The garment is often compared to a corset, since both foundation garments have rigid boning. However, a merry widow is not designed to fasten as tightly as a corset. The garment starts at the chest and ends at the top of the hips. A merry widow has half cups to support the breasts, and long garter straps to which hosiery can be attached. Typically, a merry widow fastens with a hidden zipper, and it is not very adjustable.

Initially, the merry widow was a trademark of the famous Maidenform company, which designed it for Lana Turner's role in a 1952 movie of the same name. The term “merry widow” for that type of garment caught on as more were manufactured for the general public, and Maidenform ultimately lost the trademark. Allegedly, Turner complained about the garment during filming, since her merry widow was rather uncomfortable. “I am telling you,” Turner is said to have proclaimed, “the Merry Widow was designed by a man. A woman would never do that to another woman.”

Turner's merry widow was made with contrasting panels in different fabric colors. Many merry widows are made from a solid fabric print, which may be lace, brocade, silk, or velvet, depending on the intent of the design. A merry widow which is designed to be worn under clothing such as a wedding dress tends to be simple, so that it will not interrupt the lines of a dress. When a company intends a merry widow to be worn over garments, or as a standalone piece of lingerie, it may be more richly embroidered and decorated.

As with other foundation and support garments, it is very important to try a merry widow on before purchasing one. Most merry widows are sized by bra size, so women should make sure that they know their bra size, so that they can purchase a correctly fitting garment. Since a merry widow is not very adjustable, the comfort of the fit along the body should be checked at the time of try on.