James Blunt was born in February 1974 at a military hospital in Tidworth, Wiltshire, and spent his early childhood living in England, Cyprus, and Germany, where his father, a Colonel in the British Army Air Corps and a military helicopter pilot, was posted at various times. Blunt took piano and violin lessons as a child, but his first significant exposure to popular music was at Harrow School, where he was introduced to the guitar by a fellow student, and started writing songs at age 14.
As the British Army had funded his university education (he gained an army-sponsored place at the University of Bristol, first studying Aerospace Manufacturing Engineering and then reading Sociology) Blunt was obliged to serve a minimum of 4 years in the armed forces, and joined in 1996. He took part in various exercises, from acting as the opposing army in combat training exercises at the British Army Training Unit Suffield in Alberta, Canada, to serving as an armoured reconnaissance officer in the NATO deployment in Kosovo, where Blunt and his unit worked ahead of the front lines directing forces and targeting Serb positions for the NATO bombing campaign. He led the first squadron of troops to enter Priština, and was the first British officer to enter the Kosovo capital. However, music stayed with him – he had brought along his guitar, strapped to the outside of his tank, and it was while on duty in Kosovo that Blunt wrote songs such as “No Bravery".
A keen skier, Blunt captained the Household Cavalry Alpine Ski Team, in Verbier, Switzerland, eventually becoming champion skier of the entire Royal Armoured Corps. He extended his military service in November 2000, and after an intensive 6 month army riding course was posted to the Household Cavalry Mounted Regiment in London, and stood guard at the coffin of the Queen Mother during the days of her lying in State, serving as part of the funeral procession in April 2002.

James Blunt finally left the army in October 2002 (having served 6 years) so he could pursue his musical career. It was around this time that he began to use the stage name "Blunt" ("Blount" is the original spelling of his surname, pronounced the same way, and remains his legal surname). A record contract proved difficult to achieve, with recording label executives pointing to Blunt's "posh" speaking voice as a barrier in class divided Britain, however Linda Perry, who was just launching her own Custard Records label, heard Blunt's promotional tape when visiting London, and soon after heard him perform live at the South by Southwest Music Festival. Within a few days, Blunt signed a recording contract with Perry, and a month later he was in L.A. working with producer Tom Rothrock. Thus, debut “Back To Bedlam” was born, recorded at Rothrock’s home studio, using session musicians and also with Blunt performing on many different instruments himself. It was released in the UK in October 2004. Debut single "High" (co-written with Ricky Ross of Deacon Blue) peaked below the Top 100 in the UK Singles Chart, however it was chosen to appear in a Vodafone commercial in Italy, and was subsequently a Top 10 hit there. Second single "Wisemen," was released in March 2005, but third single "You're Beautiful" proved to be the breakout hit, debuting at number 12 in the UK, climbing to number 1 after 6 weeks. It assisted “Back To Bedlam” to number 1 on the UK Albums Chart, and Blunt and his co-writers were awarded the Ivor Novello Award for “Most Performed Work”. In the US, "You're Beautiful" climbed into the Top 10 on 3 radio formats - Adult Contemporary, Adult Top 40, and Adult Alternative, and Blunt became the first British artist to top the American singles chart in nearly a decade when it reached number 1 on the Billboard Hot 100 in 2006 (the last British artist to do so had been Elton John in 1997 with "Candle in the Wind 1997"). The fourth UK and second US single was "Goodbye My Lover", released in December 2005, and 2006 saw the re-release of "High" and "Wisemen". That year also saw Blunt receive 5 BRIT Award nominations, winning 2 (“Best British Male Solo Artist” and “Best Pop Act”). “Back To Bedlam” was certified 10 times platinum and sold over 3 million copies in the UK, certified 2 times platinum and sold over 2.6 million copies in the US, and has sold over 11 million copies worldwide. It has topped the album charts in 16 territories around the world, entered the Guinness Book of Records for the fastest selling album in 1 year, and it was the highest selling album in the world in 2006.

Blunt's second studio album, “All the Lost Souls”, released in September 2007, sold 65,000 units in its first week, and was certified gold in the UK after only 4 days. Blunt completed the album's songs at his home in Ibiza, and the lyrics, melodies, and harmonies were refined for the studio recording, on which his touring band played and Tom Rothrock again served as producer. By the end of January 2008, it had sold 600,000 copies in the UK, and 3.5 million copies worldwide. The first single, "1973", was inspired by Blunt's nights out at Pacha, an Ibiza club, which opened in that year. It reached number 1 on the World Singles Top 40, and topped the Billboard European Hot 100 Singles chart. Second single, "Same Mistake", was released in early December 2007, and although it only made number 57 on the UK charts, it was number 1 in Brazil, and a hit in many other South American countries. Third single “Carry You Home" (released March 2008) fared better in the UK, reaching number 20 and brought the album back into the Top 10, 6 months after its release.
Towards the end of 2007, Blunt's also worked with French rapper Sinik, releasing "Je Réalise (which took elements of Blunt's song "I'll Take Everything") in France, scoring a top 3 hit.