Justin M. Sedell


Practice Emphasis

Divorce, complex child custody disputes, collaborative law, and high conflict litigation

Justin’s practice concentrates on divorce, complex child custody disputes, collaborative law, and high conflict litigation. Justin is an experienced trial lawyer who represents clients facing a wide range of complicated family law disputes requiring sophisticated legal advice. He has practiced in Superior Courts throughout Western Washington and represents clients in the Washington State Court of Appeals and Supreme Court of Washington.


  • Bachelor of Arts, Political Science, 2002, University of California at Davis
  • J.D., cum laude, 2005, Seattle University School of Law
  • IACP Collaborative Law Training (International Association of Collaborative Professionals)
  • IACP Facilitative Mediation Training (International Association of Collaborative Professionals)

Judicial Clerkships

  • Law Clerk, Judge Mary I. Yu, King County Superior Court, 2005-2006
  • Law Clerk, Judge Steven Gonzalez, King County Superior Court, 2006


  • “Domestic Partnerships: Another Look, Additional Rights,” King County Bar Bulletin (2009)
  • “A Family Law Practitioner’s Guide to Navigating the Domestic Partnership Expansion Bill,” Washington State Bar News, co-authored with Elizabeth Hershman-Greven (2008)
  • “Washington’s Expanded Domestic Partnership Registry Grants Important New Rights for GLBT Couples,” Perspective, co-authored with Elizabeth Hershman-Greven (2008)
  • “Legislature Acts Post-Anderson Domestic Partnership Bill Paves Way,” King County Bar Association Bar Journal, co-authored with Elizabeth Hershman-Greven (May 2007)


  • Speaker, “Family Law 101: What You Need to Know,” Pincus Professional Education (2015)
  • Co-Chair, “WSBA Community Property Seminar,” Washington State Bar Association CLE (2012)
  • Speaker, “Introduction to Collaborative Practice,” CLE for family law attorneys (2011)
  • Speaker, “Parenting Plan Litigation,” King County Bar Association CLE (2010)
  • Speaker, “Impacts of Washington’s Domestic Partnership Laws on the Elder Care Community,” CLE (2008, 2009)
  • Speaker, “Parenting Plans and the Uniform Child Custody Jurisdiction and Enforcement Act,” King County Bar Association CLE (2009)
  • Speaker, “Litigating Cases Involving Unmarried Couples,” Snohomish County Bar Association CLE (2009)
  • Speaker, “Understanding Washington’s Domestic Partnership Legislation,” Tacoma Pierce County Bar Association CLE (2008)
  • Speaker, “Relationship Agreements,” King County Bar Association CLE (2008)
  • Speaker, “Washington State’s Domestic Partner Law,” Washington ACLU Seminar (2007)
  • Speaker, Domestic Partner Law Forum, Equal Rights Washington Public Event, Tacoma, WA (2007)

Professional & Civic

Washington State Bar Association

Adjunct Law Professor, Seattle University School of Law, 2007 – present

Named as a ‘Best Lawyers’ in the area of Family Law by The Best Lawyers in America, 2019, 2020, and 2021

Named a ‘Rising Star’ by Washington Law & Politics and Washington Super Lawyers magazines, Family Law, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, and 2020

Member and prior Co-Chair, Judicial Evaluation Committee, QLaw Bar Association of Washington

Member of King County Superior Court Unified Family Court Committee

Prior Member, Alternative Dispute Resolution Committee, Washington State Bar Association

Member, QLaw Bar Association

Member, Washington State Bar Association, Family Law Section

Member, International Association of Collaborative Professionals

Member, Collaborative Professionals of Washington

Member, King County Collaborative Law