In English history, Conformists were those whose religious practices conformed with the requirements of the Act of Uniformity and so were in concert with the Established Church, the Church of England, as opposed to those of Nonconformists whose practices were not acceptable to the Church of England.

In a more general (small "c") sense, conformists are those who attempt to comply with all societal norms, generally so as to not stand out in any way and hence be subject to potential ridicule or other social sanctions.

See also: conformity