Pop star Billie Eilish

Billie Eilish is the big winner at the Grammys

The 18-year-old also won album of the year for her debut, When We All Fall Asleep, Where Do We Go, which was recorded in her childhood home in LA.

She replaces Taylor Swift as the youngest person ever to win the award.

"I joke around a lot at these things, but I genuinely want to say I'm so grateful," said the singer.

Eilish triumphed in all of the Grammys "big four" marquee categories - song of the year, record of the year, album of the year and best new artist.

She is the first person to achieve the feat since Christopher Cross in 1981.

Billie Eilish to sing the new James Bond theme

The US singer, who turned 18 last month, is the youngest artist in history to write and record a theme for the franchise.

"It feels crazy to be a part of this in every way," said the star, who called the assignment "a huge honour".

"James Bond is the coolest film franchise ever to exist. I'm still in shock."

The last two Bond themes, Adele's Skyfall and Sam Smith's Writing's On The Wall (from Spectre), have both won an Oscar.