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Mark S. Leen

Phone: 425-450-4219

Legal Assistant

Elizabeth Gossman

Direct: 425-450-4230


Mark's practice focuses on resolving real estate, business, and intellectual property disputes for individuals and businesses of all sizes as well as pursuing insurance companies who refuse to provide defenses for their insureds. Mark has handled matters pending before federal and state trial and appellate courts, the Trademark Trial and Appeal Board, and the Federal Trade Commission. Mark is presently the chair of Inslee Best's Intellectual Property Group. 

Representative Matters

  • Obtained federal trademark registrations for individual and corporate clients as well as challenged and defended trademark applications and registrations.
  • Defended a condominium association against claims of breaching its duties to owners through a jury verdict and obtained a sizable attorneys’ fee award against the plaintiffs.
  • Obtained a favorable summary judgment ruling from the King County Superior Court on behalf of a landlord in a dispute between the landlord and a tenant regarding the renewal rights of the tenant under a lease.
  • Obtained favorable summary judgment rulings from the Island County Superior Court on behalf of a private water association in a dispute regarding the ability of the association to assess an individual and the validity and scope of the association’s easements on the individual’s property.
  • Obtained the dismissal of a lawsuit involving the assertion of Section 1983 liability against a municipal client from the United States District Court for the Western District of Washington and successfully defended the dismissal on appeal before the United States Court of Appeals for the Ninth Circuit.
  • Advised a manufacturing client in relation to a claim of deceptive advertising asserted by the Federal Trade Commission.

Publications & Presentations

  • Panelist, Legal Updates, Washington Law and Resource Management Conference, June 2019
  • Presenter, Excise Tax Litigation, 2019 WASWD Spring Conference, April 2019
  • Presenter, Online Data Mining: Practice, Strategy, and Application, East King County Bar Association, April 2014
  • Condo Utilities May Be at Mercy of Assessments, King County Bar Bulletin, July 2009
  • CR 34 and Gillett v. Conner, Washington State Bar News, October 2008

Honors, Awards & Special Recognition

  • Named Rising Star, Super Lawyers Magazine, 2013-2014 & 2017

Professional & Civic Involvement

  • Washington State Bar Association, Member


Mark, a graduate of Interlake High School and lives in North Bend, Washington.  His wife Kate is the Music Director at Our Lady of Fatima in Seattle, Washington, and fills Mark’s and their four childrens’ lives with joy, beauty, and music.