In Canada and the United States, a prom (short for "promenade") is a formal dance held at the end of the second-to-last and last year of high school, called junior prom and senior prom respectively. In British English and Australian English, it is called a formal.

Boys are usually attired in tuxedos, sometimes with amazingly colored cummerbunds and bowties. Girls wear formal gowns or dresses, and often dress to shock or be noticed, choosing low cut dresses, shiny or brightly colored fabrics, unusual cuts, or formal pants outfits, adorned with a corsage given them by their date. However, some have pointed out that wearing pantsuits as a way of "standing out" is not really that much of a gesture at all considering that many girls and women hardly ever wear dresses and skirts in daily life anymore and if anything, wearing a dress or gown to Prom would be standing out from what such people did the rest of the time.

Common prom activities include dining, dancing, and socializing. Typically, high school students accumulate funds for their class prom over the four years they attend their high school though fundraisers. High schools near large cities may rent ballrooms at fancy hotels and many students group together to take limousines to their proms. Often costs are cut by using the school gym, which challenges the decorating committee to somehow mask the gym odor and drab surfaces. Regardless of venue, ear-splitting rock music is de rigueur.

The prom night is laden with significance and anxiety, about being invited, finding a date, what to wear, how much to spend, how to find the money, and whether to drink alcohol, take illicit drugs, or engage in sexual relations on the night of this pinnacle event. Some high school students feel the prom is the most romantic night of their lives. They may go in a group that includes a person they've known for years - perhaps even since Kindergarten, such as in various movies or in the family-friendly book about high school seniors, Never Let Me Go. Other times, students just try to find a date that they like. Many find it to be just as fun to attend with friends, not worrying about the dating aspect of the prom. Whichever it is, because of the age of the people, parents, teachers, or others often act as chaperones for the prom and after-prom activities. The use of chaperones prevents the occurrence of violence or fatal alcohol poisoning among attendees.

Some universities and colleges have proms as well, depending on the size of the graduating class in a faculty or department.