 | Saoirse Ronan als Christine "Lady Bird" McPherson |
 | Laurie Metcalf als Marion McPherson |
 | Tracy Letts als Larry McPherson |
 | Beanie Feldstein als Julie Steffans |
 | Lucas Hedges als Danny O'Neill |
 | Timothée Chalamet als Kyle Sheible |
 | Stephen McKinley Henderson als Father Leviatch |
 | Jordan Rodrigues als Miguel McPherson |
 | Marielle Scott als Shelly Yuhan |
 | Lois Smith als Sister Sarah Joan |
 | Odeya Rush als Jenna Walton |
 | Jake McDorman als Mr. Bruno |
 | John Karna als Greg Anrue |
 | Bayne Gibby als Casey Kelly |
 | Laura Marano als Diana Greenway |
 | Marietta DePrima als Miss Patty |
 | Daniel Zovatto als Jonah Ruiz |
 | Kristen Cloke als Ms. Steffans |
 | Andy Buckley als Matt |
 | Paul Keller als Parish Priest |
 | Kathryn Newton als Darlene Bell |
 | Myra Turley als Sister Gina |
 | Bob Stephenson als Father Walter |
 | Abhimanyu Katyal als Friendly Banker |
 | Chris Witaske als Business Jock |
 | Ben Konigsberg als David From College |
| Gurpreet Gill als Convenience Store Clerk |
 | Richard Jin Namkung als Cool Coffee Manager |
| Joan Patricia O'Neil als Danny's Grandmother |
 | Robert Figueroa als Cast Removal Doctor |
 | Carla Valentine als Guidance Counselor |
 | Roman Arabia als Luis Cruz |
 | Monique Edwards als NYC Nurse |
 | Matthew Maher als NYC Man on Street |
 | Anita Kalathara als Prom Chairwoman |
| Debra Miller als Saleswoman Joyce |
 | Georgia Leva als Senior Class Candidate |
| Derek Butler als "Merrily We Roll Along" Performer |
 | London Thor als "Merrily We Roll Along" Performer |
 | Shaelan O'Connor als "Merrily We Roll Along" Performer |
 | Christina Offley als "Merrily We Roll Along" Performer |
 | Sabrina Schloss als "Merrily We Roll Along" Performer |
 | Connor Mickiewicz als "Merrily We Roll Along" Performer |
| Erik Daniells als "Merrily We Roll Along" Performer |
| Cynthia Cales als Immaculate Heart of Mary Teacher |
| Giselle Grams als Immaculate Heart of Mary Teacher |
 | Ithamar Enriquez als Driving Instructor |
| Luisa Lee als Young Lady |
 | Danielle Macdonald als Another Young Lady |
| Adam Brock als Band Lead Singer |
| Bonnie Jean Shelton als Fab 40s Realtor |
 | Rebecca Light als Mr. Bruno's Wife |
 | Janet Song als Administrator (uncredited) |
| Scott Rudin | Producer |
| Eli Bush | Producer |
| Evelyn O'Neill | Producer |
| Nick Houy | Editor |
| Allison Jones | Casting |
| Chris Jones | Production Design |
| Traci Spadorcia | Set Decoration |
| April Napier | Costume Design |
| Jason Sack | Co-Producer |
| Sam Levy | Director of Photography |
| Jon Brion | Original Music Composer |
| Alex G. Scott | Co-Producer |
| Camilo Castano | Set Dresser |
| Gerald Palone | Set Dresser |
| Erin Walters | Key Makeup Artist |
| Dana Nelson | Set Production Assistant |
| Salvador Mejia | Driver |
| Ian Overson | Driver |
| Amanda Beggs | Sound Mixer |
| Nic Weethee | Leadman |
| Kendra Rasmussen | Assistant Production Coordinator |
| Cori Elwood | Production Office Assistant |
| Ben Harris | Casting Associate |
| Kate Wilson | Dialect Coach |
| Jan McWilliams | Script Supervisor |
| Chase Cushing | Set Dresser |
| Lannie Barcelon | Set Production Assistant |
| Andrea Clark-Meier | Stand In |
| Mark Alkofer | Studio Teachers |
| Jordan Thaler | Casting |
| Lila Yacoub | Executive Producer |
| Hannah Caldwell | Production Office Assistant |
| James Corp | Set Production Assistant |
| Merie Weismiller Wallace | Still Photographer |
| David Christenson | Transportation Captain |
| Paul Hsu | Sound Re-Recording Mixer |
| Lila Yacoub | Unit Production Manager |
| Brendan Lee | Second Assistant Director |
| Courtney Fain | Assistant Art Director |
| Lara Cilento | Key Hair Stylist |
| Jacob D. Howard | Set Medic |
| Crystal Platas | Assistant Editor |
| Perry Pascual | Property Master |
| Jacqueline Knowlton | Makeup Department Head |
| Wednesday Standley | Production Supervisor |
| Wednesday Standley | Production Coordinator |
| Ben Hall | Production Office Assistant |
| Emily Buntyn | Casting Assistant |
| Skip Lievsay | Sound Re-Recording Mixer |
| Erin McKenna | Painter |
| Paul Hsu | Supervising Sound Editor |
| Gail Carroll-Coe | Boom Operator |
| Robert Dargenzio | Driver |
| Nicholas Ramirez | First Assistant Editor |
| Suzana Peric | Music Editor |
| Joanna Glum | Production Office Assistant |
| Brian D. Hall | Driver |
| Nicholas Warren Lopez | Set Dresser |
| Xylon Jones | Assistant Property Master |
| Aubrey Marie | Hair Department Head |
| Michael Edward Smith | Location Manager |
| Rebecca Feldman | Casting Assistant |
| Jason Rico | Set Medic |
| Andrew Lim | Visual Effects Supervisor |
| Brian Ross | Music Supervisor |
| Julien Janigo | Key Grip |
| Katina Danabassis | Key Costumer |
| Louis Dargenzio | Transportation Coordinator |
| Isabel Henderson | Post Production Supervisor |
| Leanne Shapton | Title Designer |
| Danny Dougherty | Dolly Grip |
| Keith Balser | Set Dresser |
| Marissa Baram | Stand In |
| Glen Curtis | Driver |
| David Feeney-Mosier | Second Unit Director of Photography |
| Stephen MacDougall | First Assistant Camera |
| Laron Spearman | Set Production Assistant |
| Merrick Morton | Still Photographer |
| Janeen Christenson | Driver |
| Joseph Maka Langi | Driver |
| Nicholas Schenck | Sound Editor |
| Dave Anglin | Additional Camera |
| David A. Coughlin | Driver |
| Edwin Uceda | Chef |
| Justine Baker | Sound Editor |
| Heidi Griffiths | Casting |
| Michael Hill | Music Supervisor |
| Danielle Blumstein | Unit Production Manager |
| Jonas Spaccarotelli | First Assistant Director |
| Jesse Cain | First Assistant Camera |
| Jerry W. Mundy Jr. | Chief Lighting Technician |
| Jesse Kaplan | Utility Sound |
| Sedona Feretto | Stand In |
| Shawn Enright | Driver |
| Wayne Flowers | Driver |
| Teddy Blanks | Title Designer |
| Greta Gerwig | Writer |
| Matt Hovland | ADR Mixer |
| Chris O'Hara | Stunt Coordinator |
| Steve Bartek | Orchestrator |
| Ryan Hosking | Aerial Director of Photography |
| Sarah Tickal | Costume Supervisor |
| Hamzah Sarwari | Stunt Double |
| Edward Trybek | Orchestrator |
| Chris Ford | Best Boy Electric |
| Greta Gerwig | Director |
| David Feeney-Mosier | Camera Operator |
