The singer particularly took aim at white people using the phrase "all lives matter" in response to the death of Floyd, a black man who was killed by a white police officer in Minneapolis.
"If all lives matter why are black people killed for just being black? Why are immigrants persecuted? Why are white people given opportunities that people of other races aren't?" Eilish continued.
Earlier this week, a video of Floyd's death surfaced showing police officer Derek Chauvin kneeling on the neck of Floyd for eight minutes. Chauvin was later charged with third-degree murder and manslaughter.
Eilish also touched on white privilege in her post, writing, "Why is it okay for white people to protest literally being asked to stay at home while carrying semi-automatic weapons? Why is it okay for black people to be called thugs for protesting the murder of innocent people? Do you know why? White. F---ing. Privilege."
Eilish joins a long list of celebrities speaking out after Floyd's death, including Beyonce, Rihanna, Ice Cube, Ariana Grande and others. See Eilish's full post below.