 | Julia Roberts als Erin Brockovich |
 | Albert Finney als Ed Masry |
 | Aaron Eckhart als George |
 | Marg Helgenberger als Donna Jensen |
 | Cherry Jones als Pamela Duncan |
 | Veanne Cox als Theresa Dallavale |
 | Conchata Ferrell als Brenda |
 | Tracey Walter als Charles Embry |
 | Peter Coyote als Kurt Potter |
 | Michael Harney als Pete Jensen |
 | Scarlett Pomers als Shanna Jensen |
 | Scotty Leavenworth als Matthew Brown |
 | Gina Gallego als Ms. Sanchez |
 | T.J. Thyne als David Foil (1st PG&E Rep) |
 | Valente Rodriguez als Donald |
 | Erin Brockovich als Waitress |
 | David Brisbin als Dr. Jaffe |
 | Dawn Didawick als Rosalind |
| George Rocky Sullivan als Los Angeles Judge |
 | Pat Skipper als Defending Lawyer |
 | Jack Gill als Defendant |
 | Irene Olga López als Mrs. Morales |
| Emily Marks als Beth (8 months) |
| Julie Marks als Beth (8 months) |
 | Gemmenne de la Peña als Katie |
 | Adilah Barnes als Anna |
| Irina V. Passmoore als Babysitter |
 | Ron Altomare als Biker Friend |
| Charles John Bukey als Biker Friend |
 | Randy Lowell als Brian Frankel |
 | Jamie Harrold als Scott |
| Sarah Ashley als Ashley Jensen |
 | Joe Chrest als Tom Robinson |
 | Meredith Zinner als Mandy Robinson |
 | William Lucking als Bob Linwood |
 | Mimi Kennedy als Laura Ambrosino |
 | Scott Sowers als Mike Ambrosino |
 | Kristina Malota als Annabelle Daniels |
 | Wade Williams als Ted Daniels |
 | Cordelia Richards als Rita Daniels |
| Ashley Pimental als Beth (18 months) |
| Brittany Pimental als Beth (18 months) |
| Larry Martinez als Nelson Perez |
| LeRoy A. Simmons als Self |
| Don Snell als PG&E Lawyer |
 | Michael Shamberg als PG&E Lawyer |
| Ronald E. Hairston als Car Messenger |
| Scott Allen als Town Meeting Plaintiff |
 | Sheila Shaw als Ruth Linwood |
 | Matthew Kimbrough als Bartender |
| Jason Cervantes als Check Messenger |
 | Spencer Kayden als Tearful Courtroom Spectator (uncredited) |
 | Norma Maldonado als Woman #1 (uncredited) |
| Mike Malone als Baxter (uncredited) |
| Tom Tangen als Ned (uncredited) |
 | Julie Wagner als E.R. Admitting Nurse (uncredited) |
| Steven Soderbergh | Director |
| Danny DeVito | Producer |
| John Hardy | Executive Producer |
| Michael Shamberg | Producer |
| Stacey Sher | Producer |
| Carla Santos Shamberg | Executive Producer |
| Edward Lachman | Director of Photography |
| Anne V. Coates | Editor |
| Margery Simkin | Casting |
| Philip Messina | Production Design |
| Jeffrey Kurland | Costume Design |
| Gail Lyon | Co-Producer |
| Susannah Grant | Writer |
| Thomas Newman | Original Music Composer |
| John Robotham | Stunt Coordinator |
| Frederic W. Brost | Unit Production Manager |
| Kristen Toscano Messina | Set Decoration |
| Chris Lombardi | Camera Operator |
| Thomas Causey | Production Sound Mixer |
| Joseph F. Brennan | Boom Operator |
| Robin Le Chanu | Production Coordinator |
| Annie Welles | Script Supervisor |
| Christa Munro | Art Direction |
| Keith P. Cunningham | Assistant Art Director |
| Masako Masuda | Set Designer |
| Patricia Klawonn | Set Designer |
| Blair Huizingh | Art Department Coordinator |
| Richard Hartley | Rigging Gaffer |
| Robb Sullivan | First Assistant Editor |
| Kevin Hannigan | Special Effects |
| Elaine Ramires | Costume Supervisor |
| Fran Vega-Buck | Set Costumer |
| Corey Bronson | Set Costumer |
| Shoshana Rubin | Set Costumer |
| Emily Wyss | Set Costumer |
| Richard Dean | Makeup Artist |
| Bonnie Clevering | Hair Designer |
| Deborah Mills-Whitlock | Hair Department Head |
| Michelle Weiss | Hairstylist |
| Bernard Gough | Hairstylist |
| Anthony Wilson | Hairstylist |
| Ken Lavet | Location Manager |
| Carmen Cuba | Casting Associate |
| Spooky Stevens | Unit Publicist |
| Bob Marshak | Still Photographer |
| Carla Meyer | Dialect Coach |
| Chris Snyder | Construction Coordinator |
| Jon Carpenter | Transportation Coordinator |
| Shane Greedy | Transportation Captain |
| Rich Bennetti | Transportation Co-Captain |
| Larry Blake | Supervising Sound Editor |
| Larry Blake | Sound Re-Recording Mixer |
| Michael Keller | Sound Re-Recording Mixer |
| Caitlin Maloney | Post Production Supervisor |
| Monica de Armond | Post Production Assistant |
| Alicia Stevenson | Foley |
| Dawn Fintor | Foley |
| Amanda Scheer-Demme | Music Supervisor |
| Bill Bernstein | Music Editor |
| Thomas J. Smith | Visual Effects Supervisor |
| Carole Cowley | Visual Effects Producer |
| Dana Ross | Color Timer |
| Sarah Bullion | Art Department Assistant |
| Richard Boris | Greensman |
| Jason Bedig | Leadman |
| Scott Shordon | Painter |
| Francis N. 'Lucky' Costello | Standby Painter |
| Barry Idoine | First Assistant Camera |
| Charles John Bukey | Grip |
| Dale E. Anderson | Set Dressing Artist |
| Steven Kissick | Carpenter |
| Antoine Mascaro | Chef |
| Charles Drake | Craft Service |
| Loren Bess | Driver |
| Taina Mirach | Production Intern |
| Thomas S. Dickson | Projection |
| John Bullard | Propmaker |
| Joseph Keideth | Security |
| Harold Fowler | Set Medic |
| Keri Bruno | Set Production Assistant |
| Eric Flickinger | Sound Recordist |
| Marc C. Geschwind | Stand In |
| Gregory Jacobs | Assistant Director |
| Frank Endewardt | Best Boy Electric |
| Gary M. Lang | Electrician |
| Russ Caldwell | Gaffer |
| Randy Berrett | Rigging Grip |
| Ricki L. Stein | Production Accountant |
| James C. Taylor | Production Supervisor |
| James Morioka | Assistant Sound Editor |
| Thomas Pasatieri | Orchestrator |
| Dennis S. Sands | Scoring Mixer |
| Mark Tait Lewis | Digital Compositors |
| Thomas John McGowan | Studio Teachers |
| Mark Kenna | Dolby Consultant |
| John Owens | Electrician |
| Janis Mekaelian | Key Costumer |
| Ken Diaz | Tattoo Designer |
| Nicholas Wolfert | Additional Second Assistant Director |
| Michael Risoli | Second Second Assistant Director |
| Alberto Christiano Lombardo | Assistant Property Master |
| Thomas Moffitt | Set Painter |
| Erin Boyd | Swing |
| Niamh Murphy | Textile Artist |
| Ron Bedrosian | ADR Mixer |
| Brian Basham | ADR Recordist |
| Dawn Fintor | Foley Artist |
| David Betancourt | Foley Mixer |
| Jon Vogl | Foley Recordist |
| Richard Kite | Utility Sound |
| Werner Hahnlein | Special Effects Assistant |
| Roydon Clark | Stunt Double |
| Rick Avery | Stunt Driver |
| James W. Apted | Assistant Camera |
| Rodney Veto | Best Boy Grip |
| Stacy De La Motte | Camera Loader |
| Paul Threlkeld | Dolly Grip |
| Isaac Friedman | Second Assistant Camera |
| Brumby Broussard | Casting Assistant |
| John Axelrad | Assistant Editor |
| Gary Burritt | Negative Cutter |
| Caleb Duffy | Assistant Location Manager |
| Buck Damon | Music Consultant |
| Gavin J. Behrman | Assistant Accountant |
| Karen Jarnecke | Assistant Production Coordinator |
| Rich King | Extras Casting |
| Cheri Hall | First Assistant Accountant |
| Jim Swidarski | Payroll Accountant |
| Brett Brown | Production Assistant |
| J. Larsen Jay | Production Secretary |
| Peter Bankins | Property Master |
| Aaron Glascock | Dialogue Editor |
| Gary Archer | Prosthetics |
| Thomas A. Curran | Grip |
| Joni Avery | Stunts |
| Mike Malone | Set Dresser |
| Tabby Hanson | Stunt Double |
| Steve Kelso | Stunt Driver |
