Hopkins began her writing career in 1990. She started with nonfiction books for children, including "Air Devils" and "Orcas: High Seas Supermen".

Hopkins was adopted by Albert and Valeria Wagner when they were 72 and 42, respectively. Her first poem was published in the Palm Springs Desert Sun when she was nine. She attended high school in Santa Ynez Valley and went on to study journalism at the University of California, Santa Barbara before dropping out to start a family and a Business. She had two children; Jason and Cristal. When her marriage failed, she sold her Business and began freelance work. Following her divorce, she had a daughter, Kelly, with a man she considered to be a 'rebound'. He was abusive and kidnapped Kelly, keeping her in secrecy for three years. She was found later by his grandmother. Around 1991, she married John Hopkins, her current husband. They also adopted their daughter Cristal's son, Orion. In 1990, Ellen Hopkins and her family moved to northern Nevada. During this time she decided to write for a living. She started out freelancing newspaper and magazine articles, then moved from there into children’s nonfiction.

In 2006, Hopkins was recognized with a Silver Pen Award (for emerging writers) from the Nevada Writers Hall of Fame. She was inducted as a full member into the Hall of Fame in 2015.

Hopkins has since written several verse novels exposing teenage struggles such as drug addiction, mental illness,and prostitution, including Crank, Burned, Impulse, Identical, Glass, Tricks, Tilt, and Fallout. Glass is the sequel to Crank, and Fallout, the third and final book in the series, was released on September 14, 2010. Perfect was released on September 13, 2011, and is a companion novel to Impulse. Ellen Hopkins's book, Tilt, was released September 11, 2012, and is a companion from the point of view of the teens mentioned in Triangles. Hopkins felt they needed their own story after the release of Triangles.

Her second adult novel, Collateral, came out in the fall of 2012. In 2013, she released the sequel to her bestselling book Burned titled Smoke. Rumble released August 2014, is about a boy questioning his faith after his brother commits suicide. In 2015 she released Love Lies Beneath, about a woman who falls in love with a sociopath, and Traffick , a sequel to her bestseller Tricks.

Hopkins’ main inspiration comes from her daughter, Cristal. When asked how her daughter feels about Hopkins writing about her life, she stated, “First of all, the books are not only about her life. They are about my life, and the lives of our family members. The truth is… the story inside is universal. Addiction, of one kind or another, touches almost everyone. As I wrote, I understood the importance of the story. When she’s clean, my daughter understands its importance, too.” As of December 2014, Hopkins stated in her online journal that, “My relationship with my daughter, long tenuous, disintegrated completely.”