The singer and the official twitter account for James Bond confirmed the news on Tuesday.
Eilish wrote the piece with her brother Finneas O'Connell who also worked with his sister on her debut hit album, When We All Fall Asleep, Where Do We Go?
Eilish, 18, is the youngest artist ever to write and record a James Bond theme song. She follows Adele who performed the theme song for Skyfall in 2012 and Sam Mendes who performed "Writing's On The Wall" for Spectre in 2015.
"It feels crazy to be a part of this in every way," Eilish said about the opportunity to BBC. "James Bond is the coolest film franchise ever to exist. I'm still in shock."