In a 6-3 decision, the Supreme Court said federal law, which prohibits discrimination based on sex, should be understood to include sexual orientation and gender identity.
The ruling is a major win for LGBTQ Communities workers and their allies.
And it comes even though the court has become more conservative.
Lawyers for the employers had argued that the authors of the 1964 Civil Rights Act had not intended it to apply to cases involving sexual orientation and gender identity. The Trump administration sided with that argument.
Members of the LGBTQ community across the US were celebrating on hearing the news.