Song was born in Carmichael, California (a suburb of Sacramento) to a Hmong father and a Thai American mother (adopted by a Hmong family).[1][2] Her paternal grandparents were part of the Xiong clan, but changed their last name to Song when the family immigrated from Laos to America in 1975 because of the Vietnam War.[5] Her mother, Mia Song, who was diagnosed with breast cancer in 2005, is a homemaker, and her father works as a second-grade teacher.[3] Song's mother and grandmother were born in Laos.[5] She has two younger brothers, Timmy and Nathan.[3]

Song's family relocated to Los Angeles when she was 6 to support her acting career.[3] Song holds a black belt in Tae Kwon Do[2] and was named an All-American Scholar in ninth grade. Homeschooled, Song earned a high school diploma at age 16.[1][3] Song took courses at community college and online from the University of California, Berkeley[3] while majoring in psychology[1] and minoring in business.[8]

Song started in show business as a child fashion model in San Francisco, after being spotted by a talent agent at age 3 in a shopping mall.[3] She began acting with a Little Caesars commercial at age five.[9][3] She also appeared in a Barbie and Reese's Puffs cereal commercial.[5][3] Song then had a small role in the television program Thunder Alley, where she appeared in two episodes.

Song's first film appearance was the 1995 short film Requiem, an AFI student film by actress Elizabeth Sung. Song was discovered at 7 years old to play a young version of "Fong", who is played as an adult in the film by Tamlyn Tomita. The film won a CINE Golden Eagle award.[10] Song later appeared in another short film directed by Elizabeth Sung called "The White Fox".[1]

Song's first role in a theatrical motion picture was with Santa with Muscles, a 1996 independent film starring professional wrestler Hulk Hogan. Her next film appearance was in Leave It to Beaver (1997) as Susan Acustis.

Song's first major television role came in 1999 with Nickelodeon's 100 Deeds for Eddie McDowd, where she played Sariffa Chung. After this she had numerous minor television roles in 7th Heaven, Once and Again, Popular, Judging Amy, and The Nightmare Room, and appeared in Bette with close friend Ashley Tisdale in 2001.

Song starred in the 2000 Disney movie The Ultimate Christmas Present, which won her a Young Artist Award for "Best Performance in a TV Movie Comedy, Supporting Young Actress".[11]

Her 2002 appearance on The Bernie Mac Show led to a Young Artist Award nomination for the category "Best Performance in a Television Comedy Series, Guest Starring Young Actress".[12]

Her first major role in a feature film occurred the same year in the family film Like Mike, which remains her highest grossing film to date. The film also starred rapper Bow Wow. Song portrayed the character Reg Stevens; the film received positive reviews and was successful enough to spawn a sequel, although Song did not participate.

After 2002, Song continued to make guest appearances in Disney Channel shows like That's So Raven, and had minor roles in many American sitcoms. In 2002 Song appeared in Get a Clue, the first Disney Channel Original Movie to receive over 1 million viewers. She had a recurring role as Tia in the Disney Channel's Phil of the Future, appearing in seven episodes in 2004 and 2005.

In late 2004, Song starred in the Disney movie Stuck in the Suburbs, where she portrayed Natasha Kwon-Schwartz. The film received an average 4.5 million viewers which made the film the highest top rated and most viewed TV movie in 2004. The film broke records and Song quickly became a teen idol. Song appeared in three music videos for Taran Killam's "More Than Me", "On Top of the World" and "Make a Wish" as her character in the movie, Natasha Kwon-Schwartz. The music videos were featured in the film.

In 2005, Song won the role of the selfish heiress London Tipton on Disney Channel's The Suite Life of Zack & Cody.[13] The series eventually earned a 2007 Young Artist Award for "Best Family Television Series (comedy)",[14] an Emmy nomination for "Outstanding Children's Program",[15] and two Nickelodeon Kids' Choice Awards for "Favorite TV show".[16] Song won an Asian Excellence Award for "Outstanding Newcomer".[17]

As the Suite Life series became popular, Song became a featured performer on the Disney Channel, and acquired a voice role in Disney's American Dragon: Jake Long series. In 2006, Song had a voice-over role in Holidaze: The Christmas That Almost Didn't Happen, which also featured the voices of fellow Disney Channel stars Dylan and Cole Sprouse and Emily Osment.[18]

She appeared in the Disney Channel Games 2006 as captain of the Blue Team, and in the second rendition of the Disney Channel Games as captain of the Red Team. In late 2006, Song was invited to present the category for "Outstanding Lead Performance" at The NAACP Image Awards with Ashley Tisdale.

Song had her breakthrough role in 2006, starring in and co-producing the Disney Channel Original Movies Wendy Wu: Homecoming Warrior,[19] which received 5.7 million viewers[20] making Wendy Wu: Homecoming Warrior the fifth highest viewed Disney Channel Original Movie.[7] The film also received the highest rating in the history of Disney Channel Japan. To promote the film, Song traveled to Malaysia, Singapore, and Costa Rica.[21]

The film was about an average, popular American teenager, Wendy Wu (Song), whose life is turned upside down by a visit from a young Chinese monk Shen (Shin Koyamada), who claims she is the reincarnation of a powerful female warrior and the only person who can prevent an ancient evil spirit from destroying the world. Both Song and Koyamada are martial artists.

Song's performance in the movie received many positive reviews from international publications including the New York Times, TV Guide and Vanity Fair. In 2006, she won a "Disney Channel Japan" award for "Favorite Disney Channel TV Star" for her performance in the movie.

Song also was a part of the Wendy Wu ensemble win at the San Francisco International Asian American Film Festival. At age 17, she was the youngest actress to receive the award.

Song appeared in the Walt Disney Pictures film College Road Trip[22][23] with Raven-Symoné and Martin Lawrence. The film was released in worldwide cinemas on March 7, 2008. In its opening weekend, the film grossed $13.6 million, ranking #2 at the box office.[24] As of May 2008, it has grossed a total of $45 million in the United States becoming a moderate hit at the domestic box-office. To promote the movie Song and Raven-Symoné were at the Wrestlemania XXIV.

Song is currently hosting a new Disney Channel short series called Pass the Plate, which is a multicultural series produced in ten countries in association with Disney Channel.[25] Song then starred in a Disney Channel online series called London Tipton's Yay Me![26] based on the episode Tiptonline on The Suite Life of Zack and Cody.

Song is set to appear as captain of the Red Team in the third rendition of The Disney Channel Games, which is set to air on the Disney Channel on July 27, 2008. Brenda is the only contestant who is a captain of team in all three editions.

Song will return as London Tipton in a Suite Life spin-off called The Suite Life on Deck.[27] Production was delayed due to the 2007 Writers Guild of America strike. The show will be set on a cruise ship with the brothers and London attending a semester-at-sea program.

According to the Hollywood Reporter, Song is set to star in Lifetime Movie Network telefilm Special Delivery.[28] The film is about a bonded courier who transports a bratty teenager on an international flight, but realizes a trap has been set up for them when they reach the United States.

Song was set to star in American Darlings,[29] a feature film with Nicole Kidman and Jennifer Lopez. The film was never released. A Wendy Wu: Homecoming Warrior sequel, starring Song and Shin Koyamada, is set to begin filming in 2008.[30] Song had a brief cameo in the Disney Channel Original Movie Camp Rock credited as "Girl near Lake".[31]

Song was part of the Disney Channel Circle of Stars, a group of performers from several different Disney Channel television series. She took part in the recording of a version of "A Dream Is a Wish Your Heart Makes". The recording appeared on both the special edition Cinderella DVD and on the DisneyMania 4 CD. The album CD was released in April 2005 under the Walt Disney Records label. The album became the second highest peaking album in the series, peaking at #15 on the Billboard 200 and #2 on the Top Kids Audio chart for 45 weeks.[32] The album also charted in the Top Compilation Albums peaking at #2 in it's first week and managing to chart in the Top Compilation Albums for 34 weeks.[33]

Song later appeared as the leading lady in the Nobody's Angel music video for "Always Tomorrow". In 2004, Song appeared in Jesse McCartney's music video for "Good Life" and Anneliese van der Pol's music video for "Over It". Song appeared in the music videos for Taran Killam's "More Than Me", "On Top of the World", "Make a Wish" and "More Than Me" from her movie, Stuck in the Suburbs.

In 2007, Song filmed a music video for "Open Up Your Eyes", which was featured in her movie, Holidaze. Song recorded a song for Wendy Wu: Homecoming Warrior called "I'm Not That Girl". The song aired on Radio Disney and landed #2 on Radio Disney's Top 30. The song also managed to chart in the Chile's Top 100 peaking #75.[34] The song was originally called "Girl Like Me", produced by Mark Jackson Productions but was then re-recorded for the movie and Walt Disney Records.

She also sang a variety of different songs on The Suite Life of Zack and Cody. In the Suite Life High School Musical themed episode, Song performed "Bop To The Top" and "Really Great". She earlier sang "Bling Is My Favourite Thing" on the Commercial Breaks episode on Suite Life. "Bling Is My Favourite Thing" has been used in commercials for ABC's Ugly Betty, and "I'm Not That Girl" has also been used in commercials for ABC Family's Lincoln Heights. "Really Great" was the theme song for Disney Channel online series London Tipton's Yay Me!.

Ian Scott has written and produced demo songs for her.[35] In 2006, several tracks recorded by Song leaked on Scott's Myspace page. The songs leaked included "Girl Like Me", "Open Up Your Eyes" and "Hearts and Souls". In late 2007, several other songs were leaked. The songs are credited to Mark Jackson Productions, which is associated with Warner Bros. Records. Some of Songs tracks were featured in MTV's The Hills. "Open Up Your Eyes" was featured in Holidaze: The Christmas That Almost Didn't Happen.

Song has also recorded several other demo tracks (before starting production for Wendy Wu: Homecoming Warrior) with several producers. When asked if she plans to break into the music scene with an album, Song replied, "Well if the opportunity were to come about, I'd be stupid to say no."[36]

Song turned 20 on March 27, 2008 and spoke out against becoming another wild Hollywood star. "Besides Hollywood grand-openings and award shows, I try to stay away from the parties. It’s so easy to be swept away from that whole scene because it’s expected of you. I’ve never drank or smoked in my entire life, but I’ve seen 15-year-olds drinking and smoking and I just think that’s gross."[1] According to Time, Song is one of the three Disney starlets who have not been involved in the Hollywood party girl scene, along with Hilary Duff and Raven-Symoné.[37]

In 2006, Song was hostess for the "A World Of Change" annual charity fashion show fundraiser to benefit Optimist Youth Homes & Family Services.[38] Song also participated in The 10th Annual L.A. Cancer Challenge.[39] In addition as part of the Disney Channel Games 2007, Song's team supported the Make-a-Wish Foundation. Song has also participated in "Much Love Animal Rescue Shop 'Til You Drool Benefit" and "LA Mission's 2005 Thanksgiving", where she donated food to Hollywood's homeless.

In 2007, Song started hosting a Disney special daily segment called Pass the Plate, where she helps kids and their families learn more about healthy food. In 2006 and 2007, Song participated in the YMCA Healthy Kids Day in Chicago.[40]

Song ranked ninth in Netscape's "Top 10 Pretty Petites in Entertainment".[41] In December 2006, CosmoGIRL! and Popstar! Magazine named her The Queen of Disney, and the readers of Askmen.com named her "Actress of the Year". Interview ranked Song ranked #10 on its "future stars of tomorrow". Song was voted one of "AOL's Top 20 Tween (and Teen) TV Stars".[42] E! ranked Song #23 in its "50 Cutest Child Stars: All Grown Up", while FHM ranked Song #22 in its "100 Sexiest Women in the World 2006" special supplement, and number #38 in "Maxim's Hot 100 of 2006 list".[citation needed]

Song supported the Writers Guild of America West solidarity march in Hollywood Los Angeles, California on November 13, 2007. The strike started on November 5.[43]

Song currently resides in Los Angeles, California, and is represented by the International Creative Management[28] and Curtis Talent Management.