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Sigourney R. Haylock

Counsel | She/Her/Hers
Counsel | She/Her/Hers
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Areas of Focus

Overview

Sigourney is a litigator who defends companies in high-stakes commercial litigation. She regularly represents clients in the retail and consumer products, food and beverage, real estate, and healthcare sectors.
Sigourney represents clients in a range of complex commercial litigation matters, including false advertising and unfair competition, consumer class actions, product liability, and business and contract disputes. She also counsels clients on Proposition 65 compliance, pre-suit notices and threatened litigation.

In her real estate practice, Sigourney regularly advises clients on lease interpretation issues such as abatement, defaults, co-tenancy, force majeure and maintenance obligations. She understands the operational and financial pressures legal disputes can create and works closely with clients to develop strategies aligned with their business objectives.

 

Sigourney was recognized by Best Lawyers in its 2026 and 2027 “Ones to Watch” lists for commercial litigation. In 2021, she was named a “Top 40 under 40” lawyer by The National Black Lawyers, an organization that recognizes lawyers who have a reputation for providing excellent legal representation and who are leaders in their respective practice areas.

While in law school, Sigourney served as a Note and Comment Editor for the Loyola of Los Angeles Law Review and as a certified advocate in Loyola’s Youth Justice Education Clinic. She also externed for the Honorable André Birotte, Jr. in the U.S. District Court of the Central District of California.

Career & Education

    • University of California, Santa Barbara, B.A., Environmental Studies, Minor in Global Peace and Security, 2012
    • Loyola Law School, Los Angeles, J.D., 2017
    • University of California, Santa Barbara, B.A., Environmental Studies, Minor in Global Peace and Security, 2012
    • Loyola Law School, Los Angeles, J.D., 2017

    • California
    • U.S. District Court for the Central District of California
    • California
    • U.S. District Court for the Central District of California

Sigourney's Insights

Firm News | 5 min read | 08.20.26

Crowell & Moring Earns Top Honors in The Best Lawyers in America® 2027 Edition, with Two Attorneys Named Lawyer of the Year

Washington – August 20, 2026: The Best Lawyers in America® has recognized 57 of the firm's attorneys in its 2027 edition, a testament to the firm's deep bench of legal talent across practices and offices nationwide. In addition, 29 attorneys have been named to the Best Lawyers: Ones to Watch® list, recognizing outstanding attorneys earlier in their careers. ...

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Representative Matters

  • Defeated consumer class action filed against a snacking company in N.D. Ill. alleging false advertising and greenwashing over “climate neutral certified” labeling on a food company’s brand of snack bars. All claims were dismissed with prejudice, with the judge agreeing the truthful certification statement was non-deceptive and plaintiff faced no risk of future harm.
  • Represented a bakery-café against false advertising claims (clean), resulting in two successful motions to dismiss and a positive resolution.
  • Represented manufacturer of personal care products in multi-plaintiff suit regarding consumer complaints of skin irritation, hair thinning, and hair loss resulting in dismissal.
  • Defended a fashion retailer in litigation regarding co-tenancy and lease termination issues, resulting in a favorable settlement at mediation.
  • Counseled companies whose products were alleged to contain various Proposition 65-listed chemicals on regulatory compliance and threatened litigation.
  • Assisted in Prop 65 compliance counselling and violation notice investigations for companies whose products were alleged to contain various listed chemicals including lead and lead compounds, mercury, acrylamide, hexavalent chromium, DEHP and DINP.
  • Represented a medical device manufacturer in mass tort federal and state products liability suits alleging design and warnings defects, fraud, and breach of warranties.

Sigourney's Insights

Firm News | 5 min read | 08.20.26

Crowell & Moring Earns Top Honors in The Best Lawyers in America® 2027 Edition, with Two Attorneys Named Lawyer of the Year

Washington – August 20, 2026: The Best Lawyers in America® has recognized 57 of the firm's attorneys in its 2027 edition, a testament to the firm's deep bench of legal talent across practices and offices nationwide. In addition, 29 attorneys have been named to the Best Lawyers: Ones to Watch® list, recognizing outstanding attorneys earlier in their careers. ...

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Insights

Firm News | 5 min read | 08.20.26

Crowell & Moring Earns Top Honors in The Best Lawyers in America® 2027 Edition, with Two Attorneys Named Lawyer of the Year

Firm News | 1 min read | 10.29.25

Crowell Secures Victory for Mondelēz in False Advertising Alleged “Greenwashing” Suit

Client Alert | 11.17.23

Changes to Prop 65 Warning Requirements on the Horizon

Client Alert | 4 min read | 10.10.23

California Raises the Bar for Corporate Accountability as Newsom Signs the Most Sweeping Climate Disclosure Laws in the Nation

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Practices

Industries

Sigourney's Insights

Firm News | 5 min read | 08.20.26

Crowell & Moring Earns Top Honors in The Best Lawyers in America® 2027 Edition, with Two Attorneys Named Lawyer of the Year

Washington – August 20, 2026: The Best Lawyers in America® has recognized 57 of the firm's attorneys in its 2027 edition, a testament to the firm's deep bench of legal talent across practices and offices nationwide. In addition, 29 attorneys have been named to the Best Lawyers: Ones to Watch® list, recognizing outstanding attorneys earlier in their careers. ...

View All Insights