Overalls are a single garment consisting of pants, a chest covering, and suspenders or braces. Overalls are typically a utilitarian garment worn as some sort of protection in various occupations, including farm and railroad work, car racing, and military work. Some people wear overalls as a fashion statement or for comfort rather than for work. A similar garment, which covers the entire torso and arms on top, is also sometimes referred to as overalls, though it is more often called a coverall or coveralls.

Overalls may be made of a variety of materials. Perhaps the most common is denim. Denim overalls, called dungarees in England after the Indian fabric that was the precursor to denim, first became popular among British sailors and railroad workers in the United States in the 19th century. Blue jeans are also sometimes called dungarees. Denim overalls have become more common as everyday wear, particularly for young people, in recent decades, and many different colors and styles are available.

Function often determines the fabric used to make overalls. Race car drivers and drag racers wear overalls made of a fire resistant textile, such as wool or Nomex®, to protect them in the event of crashes. Military overalls are also commonly fireproof. Factory workers, mechanics, sailors, and similar types of workers may wear protective coveralls, or boilersuits, made of cotton or nylon. These coveralls are usually worn over street clothes, whereas the overalls described above are typically worn over long johns and a shirt, or only a shirt.

In Sweden and Finland, many university students wear special coveralls known as student overalls. Engineering students most often wear student overalls, but some students in other fields of study have adopted the practice. Students are assigned different colors of overalls depending upon their specific academic program, and they make the uniform their own by adding buttons, patches, and so on related to their political and personal interests, becoming something of a walking scrapbook. Students may also exchange pieces of their overalls with one another.