Ólafur Arnalds (born 3 November 1986) is a multi-instrumentalist and producer from Mosfellsbær, Iceland. Ólafur Arnalds mixes strings and piano with loops and edgy beats crossing-over from ambient/electronic to pop. Ólafur was a drummer of hardcore/metal bands Fighting Shit and Celestine, as well as others.

On 12 October 2007, Ólafur's first solo album Eulogy for Evolution was released. It was followed by the EP Variations of Static in 2008. In the same year, Ólafur toured with Sigur Rós. He is also reported to have sold out The Barbican Hall in London.
In April 2009, Ólafur composed and released a track daily for seven days, instantly making each track available within 24 hours from foundsongs.erasedtapes.com. The collection of tracks was entitled Found Songs. The first track was released on 13 April.

On October 3rd 2011, Ólafur started another seven-day composition project similar to Found Songs, this one entitled Living Room Songs. The tracks were made available at livingroomsongs.olafurarnalds.com/ each day throughout the week. The project was released as an album on December 23rd, 2011.

In November 2012 Ólafur Arnalds announced a new partnership with the Universal Music label Mercury Classics. The first album to be released on the label is titled "For now I am Winter" and announced for international release in February 2013.
Ólafur Arnalds has been involved with various other projects and has his music appear in many films, television shows and advertisements. The track Brotsjór was featured on So You Think You Can Dance Season 8. He also spoke at length on the subject of fan-submitted art in the 2011 documentary film, Press Pause Play. His song Til Enda was used in a trailer for a 2012 film Looper, starring Bruce Willis. More recently, he has composed the score for the 2013 ITV series Broadchurch.

Ólafur's cousin Ólöf Arnalds is also a well known singer/songwriter.