Overview
Joanna represents employers in a wide range of employment litigation matters, with a focus on complex wage and hour class, collective, and Private Attorney General Act (PAGA) actions in both state and federal courts.
She has successfully defended both large and small companies in high-stakes litigation, including cases involving novel legal issues and matters of first impression. Joanna works closely with her clients to develop litigation strategies that align with their business objectives.
In addition to her wage and hour practice, Joanna regularly represents employers in single-plaintiff and multi-plaintiff lawsuits involving claims of discrimination, retaliation, harassment, and other workplace disputes. She is experienced in discovery management, fact development, legal research, motion practice, and courtroom advocacy. Joanna also provides day-to-day counseling to employers to help prevent litigation and ensure compliance with employment laws. Fluent in Spanish, she regularly applies her language skills to support clients with diverse workforces.
Joanna’s international background and prior experience as an analyst for a leading oilfield services company give her a unique, business-minded perspective. She is known for her hands-on approach to client service, whether that means defending employers during government audits at farms, dairies, or manufacturing sites, or tailoring her legal strategies to meet the specific operational needs of each client. Before joining Constangy, Joanna practiced at national and international law firms, including Littler Mendelson and Baker McKenzie.
Honors & Recognition
- The Best Lawyers in America® "Ones to Watch" for Litigation - Labor and Employment (2021-2025)
- Southern California Super Lawyers® "Rising Stars" honoree (2021-2022)
About Me
Joanna was born in Peru and lived as an expatriate in countries such as Chile, Indonesia, and Singapore during her childhood. She attended high school in Jakarta, Indonesia, and graduated from Jakarta International School before moving to the United States to attend university. Joanna currently lives in Los Angeles with her husband, Duncan, and a Labrador-mix rescue named Pumpkin.
Credentials
Education
Emory University School of Law
- J.D., 2011
Arizona State University
- B.S., magna cum laude, 2009
Languages
- Spanish
Media
News
Events
Constangy Streaming
Joanna E. MacMillan, Partner - Los Angeles, CAJoyce M. Dos Santos, Associate Attorney - Boston, MA
Professional & Civic Associations
Professional
- Century City Bar Association
- President (2023-present)
Services
Admissions
- California, 2012
- New York, 2015
"Alone we can do so little; together we can do so much."
Helen Keller
