During her set she brought out her brother Finneas and the pair performed 'Try Not To Abuse Your Power', in protest of the decision made today that will see millions of women in the US lose the right to a safe abortion.
Before performing the song, Billie said: "Today is a really, really dark day for women in the US and I'm just going to say that because I can't bare to think about it any longer at this moment."
She then launched into an incredible rendition of her hit song that felt all the more pertinent given that the singer is one of many young US women who are having to deal with living in a country that clearly doesn't respect their rights.
This isn't the first time that Billie has spoke out about the massive blow to women's rights.
In an interview with NME published today, the star explained how she was baffled by people's pre-occupation with Johnny Depp and Amber Heard's trial, when millions of women are having their right to choose taken away.
"I was in this state of depression, losing my own rights to my own body, and then I’d go on the internet and it would be people giving their take on this trial."
She went on to add: “Who f****** gives a f***? Women are losing rights for their bodies, so why are we talking about celebrities’ divorce trials? Who gives a s***? Let them figure it out on their own. The internet bothers the s*** out of me sometimes."
The move to overturn the landmark case that has protected women's rights to abortion in the US comes as the Supreme Court ruled in favour of the state in the Dobbs v Jackson Women's Health Organization case, in which the state of Mississippi argued for a new law that would ban abortion after 15 weeks of pregnancy.
The court ruled in favour of the state by a majority vote of six to three, in turn making it so individual states across North America will now be able to introduce bans on the procedure.
Half of the states in the country are already expected to introduce new restrictions or bans, with 13 states, including Texas, Louisiana and Mississippi having already passed so-called trigger laws that mean a ban on abortion will automatically go into effect following the Supreme Court's ruling.
Others will reactivate dormant laws that will in many cases make it illegal to access abortion, possibly even when the conception has resulted from rape or incest.
The news came today as Billie prepared to take to the Pyramid Stage.