For Independence Day, he received a Grammy Award for Best Instrumental Composition Written for a Motion Picture or for Television, and for Sherlock, he and co-composer Michael Price won a Creative Arts Emmy[1] for the score of "His Last Vow", the final episode in the third series.

In addition, he has scored various comedies, dramas, and nineteenth-century period pieces, as well as providing music for several British television shows including the 2000 remake of Randall and Hopkirk (Deceased) and Little Britain.

Arnold performed his debut orchestral concert, showcasing his film and television music, on Sunday 6 July 2014 at London's Royal Festival Hall.

[7] The line-up featured Nicholas Dodd conducting, David McAlmont as surprise guest vocalist ("My secret weapon!"

He was also the special guest at 'The music of David Arnold[14]', a concert in Lucerne in October 2015, with Ludwig Wicki conducting the 21st Century Symphony Orchestra and Chorus.

David Arnold gave a pre-show talk about his work and the Royal Philharmonic Concert Orchestra and Maida Vale Singers (conducted by Gavin Greenaway) performed the original music while the film screened.

John Barry, the composer of many of the themes on the album, was complimentary about Arnold's interpretation of his work; "He was very faithful to the melodic and harmonic content, but he's added a whole other rhythmic freshness and some interesting casting in terms of the artists chosen to do the songs.

"[21] Barry contacted Barbara Broccoli, producer of the then-upcoming Tomorrow Never Dies, to recommend Arnold as the film's composer.

Arnold is the second cousin of Irish singer-songwriter Damien Rice, and is an ambassador for aid agency CARE International in the UK.

[30] In October 2015 he collaborated with Lethal Bizzle and Sinead Harnett to create a song combining orchestral, grime and soul elements.

He and Sherlock co-composer Michael Price also composed the music for ITV's Jekyll and Hyde television series which premiered in October 2015.

Later in 2020, he co-produced an orchestral cover of 'My Favourite Things' (from The Sound of Music) along with Richard Jones (of The Feeling) for Sophie's 2020 compilation album Songs From The Kitchen Disco.

In July 2023, it was announced that Arnold and Ellis-Bextor would collaborate with lyricist Don Black for the track to Channel 4 and Universal Pictures film, "Mog's Christmas", based upon the children's book series by Judith Kerr.