Like other forms of discrimination, religions discrimination, defined as the unfair treatment of a person based on religion, is prohibited according to the laws of the United States. Under the First Amendment of the Constitution, an amendment adopted in 1791, all citizens are granted with the right to exercise their choice of religion. In addition to this law, religions discrimination also violates federal legislation known as the Civil Rights act, which makes it illegal for people to be treated unfairly because of their religion. Employers may be required to let their employees maintain necessary religious practices during the course of the work day, such as the wearing of religious garments or praying after lunch.

However, not all religious practices are protected under the law. If a practice is so extreme that it violates law or causes harm, it is not necessarily lawful. While the government cannot prevent a person from upholding a certain belief, they can prevent them from practicing it. So although a Supreme Court religions discrimination case held that a religious club in a school is legal, it would not be legal for those involved to perform harmful or extreme practices.