Alawsuit filed by one person on behalf of that person plus all similarly situated individuals is referred to as a(

The answer is class action.

Explanation:

A class action consists of a type of lawsuit in which one of the parties involved refers to some people. A member of the group is in charge of representing that group of people collectively. The class action was established in the United States and it still has an impact in this country.

However, some European countries as well as Canada that have civil law, have implemented some changes to give consumer organizations the possibility to make claims involving consumers.  

answer; fair labor and standard act;