James is a singer/songwriter with a piano-based style. He cites taking inspiration from 1970s artists James Taylor, Bob Dylan, Paul Simon and Stevie Wonder, as well as more current artists like Ryan Adams and Death Cab For Cutie.

James was born Brendan James Ernst in Nashua, New Hampshire on 17 July 1979, to parents Patricia and Randy, and is of Irish and German descent. He moved to Derry, New Hampshire, when he was four and, after the divorce of his parents, alternated living between Derry and nearby Manchester, New Hampshire. James had an early interest in performing and singing, leading him to perform in school plays and musicals while growing up. He attended high school at Pinkerton Academy in Derry. After the death of a friend's mother, James sang "Candle in the Wind" at her funeral with a local music Teacher he knew, Kevin Kandel, accompanying him on piano. The collaboration began a friendship between the two and Kandel helped spur James's interest in music.

After graduating high school James went on to attend college at the University of North Carolina, beginning with a major in Voice before switching to Communications. During breaks from school he would head back to Derry and meet up with Kandel, who persuaded James to learn an instrument. James began teaching himself piano at the age of 19 and also started writing and composing songs. Back at the University of North Carolina, James joined the Clef Hangers, an a cappella group. With the Clef Hangers he would sing solo covers of "I Can't Make You Love Me", "Father Figure", and "Die Without You," songs that were later released on compilation CDs from the group. During his Junior year of college, wanting to pursue a career in music, he left UNC and went to Hollywood. He earned school credits during the stay on the condition that he accept an internship at a Business related to his Communications degree. While living in Los Angeles, he played at a club called The Crooked Bar (located underneath the Coconut Teaszer), while working on songs and performing. When his internship ended he returned to the University of North Carolina to complete his Communications degree, which he obtained in 2002.

After graduation from college, James had planned to return to Los Angeles and focus on his music career, even paying a rent deposit for an LA apartment. However, he changed his plans and decided to move to New York City following a day visit to the city. He worked at a job at Urban Outfitters to support himself. He held that job for the next three years while also performing at open mikes in the East Village. Around this time he also began breaking into various hotels, ballrooms and schools in order to use a piano to practice with pianos so he could practice. In 2003 he partnered with his still-current manager Ben Singer, a former classmate James had met at UNC. Ben helped him record a demo that eventually made its way to Carly Simon, who invited James to come and record a song with her. The song, "Let the River Run", would play at the 2003 Nobel Peace Prize ceremony.

In 2005 James would record another demo, this time professionally produced by Tony Bruno in Woodstock, New York at the Millbrook Sound Studio. The demo caught the interest of major labels and James did a showcase at The Living Room in New York City for various record companies. After the showcase, James was invited to Los Angeles to play for Capitol Records CEO Andrew Slater. Slater signed him to a record deal and James spent the next year and a half working on his debut album, recording with producers Tony Bruno and Patrick Leonard. Production of the album was wrought with difficulties: re-recording, disagreements over artistic direction and waiting on record label decisions extended the production. After re-recording the album with a new Producer, it was almost ready to be released when James was dropped from Capitol Records following the merger and takeover of Capitol by Virgin Records. James, along with many other artists, was dismissed from the newly merged label, but was allowed the keep his master tapes and was given a severance package.

Still living in New York, James used and built upon the music he developed and recorded at Capitol, working to release the album himself. He recorded material from the Capitol album with Los Angeles-based Producer Mikal Blue, turning it into James's self-released EP, The Ballroom Break-In, in 2007. The title of the EP was based on his early days in New York City, when he broke into venues in order to practice playing and writing songs on a piano. After the release of the EP, Tomas Young, a paralyzed Iraq War veteran, heard one of its songs, "Hero's Song," on iTunes. Young picked the song to be on a Soundtrack of a documentary of his life, called Body of War. Music from his EP was also used in television shows, including "The Sun Will Rise" which appeared on the ABC drama Private Practice in 2007. James and Blue quickly followed up The Ballroom Break-in with the full-length album, The Day Is Brave. The album used most of the material from the EP and some of the Capitol songs, but also contained new material James had written. As his EP's exposure grew, including a feature on Perez Hilton, James again gained the interest of major record labels. In 2008 he signed with Decca Records.

Decca Records released Brendan James's debut album, The Day Is Brave on 3 June 2008, in the United States, and on 17 June 2008 in Canada. It debuted on the Top 10 Billboard Heatseeker Charts, with Newsweek and Entertainment Weekly praising his debut effort. The album's single was "Green" and a music video was produced for the song. James initially toured regionally to support the album, headlining his own shows and also opening for artists such as Corinne Bailey Rae, John Legend, Susan Tedeschi, The Fray, and Robert Cray. At the end of 2008 James went on his first national tour, headlining on the MTV SoundTRACKER Tour.

Writing for James's second album began in early 2009 after the MTV Soundtracker Tour had ended. James moved from New York City to Los Angeles, where he is currently based, after having spent much time there in the past few years. Writing and production lasted for the next year and James said the second album was "far more difficult to write than my first." He traveled to London to make the album but the production work done there was scrapped. He eventually started working with Producer Warren Huart back in Los Angeles and finished the album there. During the creation of his second album James embarked on more touring, including notable tours with John Mayer's Mayercraft Carrier 2 in March 2009 and one sponsored by scooter-maker Vespa in May 2009. The Vespa-sponsored "green tour" with Jason Reeves and Amber Rubarth saw them traveling the California Coast on Vespa scooters while focusing on environmental friendliness. James was also getting his songs on more television shows, like So You Think You Can Dance, Bones and Army Wives.

James's second album, the self-titled Brendan James, was completed in 2010 released on 7 September 2010. The album debuted at #93 on the Billboard 200, making it more successful than his previous album. The album's single was "The Fall" and again a music video was made, this time featuring Melissa Ordway as the female lead. The song "Stupid for Your Love" was also available for free on James's website as part of the album promotion. Touring to support the album continued through 2010 and into early 2011, with a notable tour with musician Matt White.

In November 2011 James announced via his Twitter account that he was planning on releasing a new album of 10 songs in February 2012. This was pushed back to July 2012.

Hope in Transition was released on 10 July 2012 via Rock Ridge Music.

The album, titled "Simplify", was released on August 6, 2013.