The Brit Award-winning songwriter, 29, is the older brother of fellow singer John Newman and has co-written tracks for the likes of Ed Sheeran, Calvin Harris, Rudimental and Olly Murs.
My Last Breath was unveiled on the official Eurovision UK Twitter account this morning.
"It's such an honour to be representing the United Kingdom this year at Eurovision - I still can't quite believe it!" he said. "I'm also so proud to be taking My Last Breath as the song.
"I wrote it with some of my best friends, who are also amazingly talented songwriters in their own right. I knew it was 'the one' after first recording it, I just loved the simplicity and universal message of the song."
Newman will be hoping to win over the judging panel and European voters when he performs the track at Rotterdam’s Ahoy Arena at the grand final on May 16.
The musician won a Brit Award in 2014 for co-writing Rudimental and Ella Eyre’s Waiting All Night. He also co-wrote 2011’s winning Eurovision entry, Azerbaijan’s Running Scared.
The announcement comes after a major shake-up in the decision-making process.
While the British public has previously chosen its Eurovision entry by voting for acts in the televised competition Eurovision: You Decide, this year saw the BBC pick the act in collaboration with record label and publisher BMG.
My Last Breath will be released as a single by BMG, who previously published Sweden’s winning entry Heroes in 2015. Netta, who scored a victory for Israel in the 2018 competition, also signed a deal with the label following her win.
BBC Studios said that BMG shared its “vision of selecting a song with broad international appeal and securing an artist who embodies the spirit and values of the Eurovision Song Contest.”
The UK has not won Eurovision since 1997, when Katrina and the Waves triumphed with Love Shine A Light, and has not reached the top 10 since 2009, when Jade Ewen came in fifth place with the ballad It’s My Time, written by Andrew Lloyd Webber.
The Eurovision Song Contest will take place from May 12 - May 16 in Rotterdam, Netherlands.