Brett Dennen (born October 28, 1979) is a folk/pop singer-songwriter from Oakdale, California.
In 2004, Dennen released his first self-titled album, Brett Dennen. His second album, So Much More, including the singles “Ain’t No Reason”, “She’s Mine” and “Darlin’ Do Not Fear”. Dennen also contributed a cover of “Private Life” to the 2006 tribute album Drink To Bones That Turn To Dust: A Toast To Oingo Boingo. Dennen’s music has been featured in several television shows, including Roadtrip Nation on PBS, Grey’s Anatomy, the House episode “Family”, The Unit episode “Freefall”, and the Scrubs episode “My No Good Reason”. He also appeared live on The Tonight Show with Jay Leno on April 8, 2008, Late Night with Conan O’Brien on February 9, 2009, and The Ellen DeGeneres Show on April 21, 2009. In addition to television series, Dennen’s music has also been used in national advertising campaigns for companies such as Hilton Hotels.
He has toured extensively across the U.S. with his band (including drummer Randy Schwartz), supporting such musicians as John Mayer and guitar duo Rodrigo y Gabriela. In 2007, he toured with Guster and singer-songwriters Meiko and Joshua James.
Dennen has been a part of The Mosaic Project, a San Francisco Bay Area-based non-profit organization, since its inception. The Mosaic Project works towards a peaceful future by uniting young children of diverse backgrounds, providing them with essential skills to thrive in an increasingly diverse society, and empowering them to strive for peace. As The Mosaic Project’s Resident Rock Star, Dennen created an original musical curriculum for the program, which they released as an album called Children’s Songs for Peace and a Better World, in 2003. It won a Children’s Music Web 2004 Award  and a Parent’s Choice 2004 Approved Award.
In November 2007, Dennen was named as one of Rolling Stone Magazine’s “10 Artists To Watch.”
In 2008, Entertainment Weekly named Dennen one of its eight “Guy on the Rise” After a spring tour co-headlining with Mason Jennings and Missy Higgins, Dennen entered the studio to record his 3rd album. He spent the summer of 2008 on tour with John Mayer and Colbie Caillat, playing festivals such as the Rothbury Music Festival in Michigan, Telluride Bluegrass Festival and the Mile High Music Festival in Colorado.
Dennen is currently signed to Downtown Records through a partnership with Dualtone. 
In 2008, Dennen, along with Jason Mraz, contributed the song “Long Road to Forgiveness” to the Survival International charity album Songs for Survival. Earlier in the fall, Dennen toured Australia with Pete Murray. In late October, Hope for the Hopeless, Dennen’s third album, was released on the Downtown/Dualtone partnership. The song “Ain’t Gonna Lose You” was featured on Grey’s Anatomy and topped the iTunes folk charts. The record reached number 6 in the digital charts, and was followed by a successful mini-tour.
In January 2009, Dennen embarked on a 3-month headlining tour of the US, with support acts Erin McCarley and Angus & Julia Stone. Dennen also announced plans to tour the UK and Europe, including a show at the Hoxton Bar & Kitchen in London on the 7th May. In 2009, Brett’s song “Ain’t Going to Lose You” was also used in the closing sequence of an Ugly Betty episode.