Erika Christensen was born in Seattle, Washington on August 19, 1982. There she started her education in the Montessori school system until she moved to Los Angeles with her family at the age of four. She then entered the Delphi Academy and gravitated to an artist's career at an early age. At eleven Erika started singing, dancing and acting with professional children's theatre groups as well as volunteering to perform for foster family events and community groups. Within a year, Erika had performed in hundreds of shows throughout Southern California and in many venues including The Serendipity Theatre Company and the Pasadena Dance Theatre. At the age of twelve Erika declared her life-long goal was to be an actor. She immediately started working professionally and enrolled in a school that allowed her to continue her academic studies while working on film sets. At thirteen, she landed the coveted role of "Karen", Wally Cleaver's girlfriend in Universal Picture's feature film Leave It To Beaver. Her performance was critically noted for the chemistry she brought to the character.

Erika then graduated from the Voyager Charter School at the age of sixteen with a 4.0 grade average at the top of her class of 1998. She continued to hone her skills by performing in popular television shows and gravitated to more dramatic roles where she was nominated for the Best Performance by a Young Actress in a TV Series Drama. Then at seventeen, Erika stunned audiences as Michael Douglas' drug addicted daughter in Steven Soderbergh's Oscar and Golden Globe winning film, Traffic. Erika had never taken drugs herself, so she turned to the drug rehabilitation group Narconon to research her role. Her performance was disturbingly real and she, along with the rest of the cast, received the prestigious Screen Actor's Guild Award for their work. Erika individually received the Movieline Award for "Standout Performance" and MTV's "Breakthrough Performance Female" Award for her role.

Also in 2002, Erika played the daughter of an ex-groupie [Susan Sarandon], in Fox Searchlight's, The Banger Sisters costarring Goldie Hawn and Geoffrey Rush. She also starred in the 20th Century Fox film Swimfan which debuted as #1 at the box office and in which she reprises a classic femme fatale role in a love triangle. In the summer of 2002 Erika filmed Paramount Picture's, The Perfect Score, due to be released in September of 2003. Erika supports various charity events including the Ronald McDonald House for children with cancer and the Hollywood Police Activities League. She also supports the Mothers Against Violence in America (MAVIA) and Students Against Violence (SAVE) through her donated drawing which appears on the cover of their fund-raiser calendars and has designed a car for auction to benefit the Save the Music Foundation. In 2002, Erika was the keynote speaker at the National Foundation for Women Legislators Conference in Washington D.C. In her speech, Erika proclaimed that through her research, she knows rehabilitation is not only possible, but can be achieved regularly if we use the right tools.