Troop and troupe sound alike, but they refer to different kinds of groups.
Use troop for a group of soldiers or scouts. It is common in military contexts and in organizations like the Scouts. For example, The scout troop cleaned the park on Saturday.
Use troupe for a group of performers, especially actors, dancers, or comedians who work together. For example, The theater troupe is touring three cities this month.
- Troop: soldiers or scouts
- Troupe: performers
A simple memory tip can help: troupe has an extra u, and many performing groups are made up of unique artists. If you are writing about a stage, tour, dance company, or comedy group, choose troupe. If you are writing about the military or scouting, choose troop.
Try this contrast: The troop set up camp before dark. But The troupe rehearsed before the show. The words may sound similar, but the setting makes the correct choice clear.