A Scout is a child, usually 10–18 years of age, participating in the worldwide Scouting movement. Because of the large age and development span, many Scouting associations have split this age group into a junior and a senior section. Scouts are organized into troops averaging 20–30 Scouts under the guidance of one or more Scout Leaders or Scoutmasters. Troops subdivide into patrols of about 6–8 Scouts and engage in outdoor and special interest activities. Troops may affiliate with local, national, and international organizations. Some national Scouting associations have special interest programs such as Air Scouts, Sea Scouts, outdoor high adventure, Scouting bands, and rider Scouts. In the USA there was around 6 million scouts in 2011.

A Scout leader or Scouter generally refers to the trained adult leader of a Scout unit. The terms used vary from country to country, over time, and with the type of unit.