Erin Brockovich-Ellis (born June 1960) is a woman who, despite lack of formal education, in 1993 was instrumental in constructing a case against the $30 billion Californian Pacific Gas and Electric Company (PG&E), alleging contamination of drinking water with hexavalent chromium in the southern Californian town of Hinkley. The case was settled in 1996 for $333 million, the largest settlement ever paid in a direct-action lawsuit in U.S. history.

Continuing to work with the lawyer Ed Masry, she went on to participate in other anti-pollution lawsuits. One accuses Whitman Corp of chromium contamination in Willits, California, and another with 1,200 plaintiffs alleges contamination near PG&E's Kettleman Hills plant in Kings County.

The story of Erin Brockovich's first fight against PG&E was turned into a 1998 film of the same name directed by Steven Soderbergh and featuring Julia Roberts as Erin Brockovich, a role for which she won the Academy Award for Best Actress. Erin Brockovich has a cameo in this film as a waitress named Julia.