A corsage /kɔːrˈsɑːʒ/ is a small bouquet of flowers worn on a woman's dress or around her wrist for a formal occasion. They are typically given to her by her date. Today, corsages are most commonly seen at homecomings, proms, and similar formal events.

In some countries, similar ornaments are worn by the mothers and grandmothers of the bride and groom at a wedding ceremony.

Flowers worn by men are generally called buttonholes or boutonnières. At school events such as homecoming or prom, male-female couples generally coordinate the corsage and boutonnière, signifying their connection, and distinguishing them from others. In some cases, young girls may wear a corsage to a father-daughter dance, and the father may also wear a boutonnière.

Wearing flowers pinned to clothing dates as far back as Ancient Greece, when small bunches of fragrant flowers and herbs were worn at weddings to ward off evil spirits. During the 16th and 17th centuries, corsages and boutonnières may have been a part of daily life to prevent disease and to ward off evil spirits, but over time, they became special-occasion pieces.

The word corsage comes from the French term bouquet de corsage, meaning a bouquet of flowers worn on upper part of the body ("corsage" meaning girdle, bodice in French), which was traditionally worn by women to weddings and funerals. Eventually, the term shortened to corsage in American English. In the early 19th century, corsages were regarded as a courting gift and were often given at formal dances. Traditionally, the gentleman would bring a gift of flowers for his date's parents and would select one of the flowers to give to his date, which would then be carried or attached to her clothing, usually on the front of the shoulder. During the 1950s, some corsages were made with fruit and would be seen on hats for decoration. As dress styles changed, pinning the corsage to the dress became impractical, and wrist corsages became the norm.

Today's corsages are similar to those made in previous decades, though generally smaller. It is still customary for someone to give their female date a corsage when attending a formal dance, but they are also sometimes given to a daughter attending a formal event by her parents or worn by the mothers and grandmothers of the bride and groom at a wedding. Wives and any surviving mothers typically wear corsages at Anniversary celebrations; generally, the flowers are the same as what was used at the wedding, with ribbons indicating the milestone, (i.e. silver for 25th, red for 40th). Florists recommend that the flowers be complementary in color to the attire, and corsages and boutonnières should be coordinated to indicate that a couple is attending the event together. Corsages are often dried and pressed to be preserved as mementos.

When attending a school formal or prom in the US, providing a corsage for a prom date signifies consideration and generosity, as the corsage is meant to symbolize and honor the person wearing it. Corsages are usually worn around a prom date's wrist; alternatively, they may be pinned on her dress or a modified nosegay can be carried in her hand. The colors of the flowers are usually chosen to complement the dress or to add color to the couple, creating a unifying look. Prom couples may wish to go together to choose the flowers for a custom-made corsage or boutonnière. Traditionally, the male presents a corsage or nosegay to the female as a gift, while the female would provide the boutonnière and pin it on the male's shirt or jacket.

Given to a student by a date or parent to wear on homecoming day, homecoming chrysanthemums ("mums") are an over-100-year-old tradition in the U.S. associated with the emergence of homecoming football games at universities and colleges, especially in the South and Midwest. After World War II, it became popular for homecoming mum corsages to be adorned with ribbons in school colors to signify school spirit. Some sources identify the University of Missouri, Southwestern University, and Baylor University as the first universities to host homecoming festivities. Soon after, homecoming games and traditions spread to high schools. In these early years, the chrysanthemum was typically used as the homecoming corsage flower because of its heartiness, popularity, and seasonal availability.