
Credentials
Education
Clerkships
Judicial Clerk to The Honorable William C. Griesbach, U.S. District Court for the Eastern District of Wisconsin
Law Clerk, Department of Justice, Civil Division
Recognition
Chambers USA
Colorado Commercial Litigation, 2026
Benchmark Litigation
Future Star, 2021-2026
40 & Under Hot List, 2023-2026
The Best Lawyers in America
Ones to Watch - Commercial Litigation, 2021-2022, 2024-2025
Ones to Watch - Mass Tort Litigation / Class Actions - Defendants, 2021-2023
Ones to Watch - Product Liability Litigation - Defendants, 2021-2022, 2024-2025
Ones to Watch - Litigation - Labor and Employment, 2024-2025
Colorado Super Lawyers
Super Lawyers, Business Litigation, 2023-2026
Rising Stars, Business Litigation - 2021
Rising Stars, Personal Injury - Products Defense, 2018-2020
Bar and Court Admissions
Colorado
Illinois
Wisconsin
U.S. Court of Appeals, 11th Circuit
U.S. District Court, D. Colorado
U.S. District Court, N.D. Illinois
U.S. District Court, W.D. Wisconsin
Legal Memberships
Colorado Women’s Bar Association Foundation
Board of Directors, present
Leadership Council on Legal Diversity
Mentor, 2022 - present
Fellow, 2022
Colorado General Counsel Mentoring Program
2018-2020
International Association of Defense Counsel
Member
Articles and Presentations
Co-Author, "Trial by Webcam: Tips From a Firsthand Experience," Law360.
Author, "Colorado Supreme Court, following US Supreme Court's ‘Bauman,' Rejects Broad General-Jurisdiction Theory," Washington Legal Foundation's The Legal Pulse.
Co-Author, "The Affordable Care Act and Colorado's Collateral Source Rule," Denver Law Journal.
Presenter, "How to Safely Use AI to Excel in Law," Faculty of Federal Advocates.
Presenter, "Artificial Intelligence Will Be a Litigator's Best Friend," The Trial Network.
Presenter, "How the Plaintiffs' Bar is Moving Away from Reptile Theory Toward Strict Compliance," The Trial Network.
Presenter, "Practical Considerations to the Reasonable Alternative Design Test," In-house counsel.
Presenter, "WTO WILLS: Taking Ownership of Your Career."
Marissa Ronk represents sophisticated clients in complex commercial litigation and class and mass actions. She is a strategic leader, setting the direction and development of major cases to establish priorities, challenge and frustrate opponents, and create opportunities. Marissa builds case strategies that align with clients’ business goals and values. Rather than react to opponents’ moves, she designs litigation plans that exploit pain points and increase leverage for her clients, whether as a plaintiff or defendant. For example, she often develops counterclaims and pursues aggressive discovery to take an upper hand.
Marissa serves on WTO’s management committee and chairs the firm’s attorney review committee. Prior to joining WTO in 2015, she worked in the litigation department of Winston & Strawn in Chicago.
Cases
Commercial Litigation
Secured complete indemnification and no future liability for a green energy manufacturer in a supplier dispute involving a recall of the client's products.
Achieved favorable resolution of a multibillion-dollar commercial dispute for an oil and gas company in an asset purchase dispute.
Commercial Litigation
Secured complete indemnification and no future liability for a green energy manufacturer in a supplier dispute involving a recall of the client's products.
Achieved favorable resolution of a multibillion-dollar commercial dispute for an oil and gas company in an asset purchase dispute.
Served as co-counsel to an oil and gas company in an $80 million dispute. During mediation, we helped effect a buyout solution resulting in valuable land rights and resolving the lawsuit for a small fraction of what it would have cost to settle.
Obtained financial and other relief for a manufacturer in business and trade secrets matters.
Recovered all funds claimed in a breach of contract dispute between two Fortune 20 companies.
Represented General Electric Co. in an international arbitration hearing that resulted in a settlement, after the hearing concluded, for more than 90% of our client’s claim.
Class & Mass Actions
Serving as lead national trial counsel to a major U.S. distributor of vaping products in federal multidistrict litigation in California. We are liaison counsel to all of the distributor defendants in the litigation.
After prevailing on a motion to dismiss all of plaintiffs' nationwide class claims, settled all claims individually for a major appliance manufacturer in a class action involving the doors in all of its microwave ovens.
Served as co-counsel in an oil and gas putative class action alleging violation of royalty rights. An early and aggressive discovery strategy persuaded the plaintiff to walk away from the matter.
Won a motion to dismiss with prejudice a putative class action in federal court in California. The plaintiff alleged violations of the Federal Fair Debt Collection Practices Act (FDCPA) and California's Rosenthal Fair Debt Collections Practices Act.
Represented a major Colorado manufacturer in its winning motion to dismiss class action litigation alleging illegal pesticide use.
Defended several manufacturers of high fructose corn syrup in a multimillion dollar dispute in which the plaintiff alleged her consumption of the product caused her diabetes. The Western District of New York dismissed the complaint with prejudice and that dismissal was upheld by the Second Circuit.
Represented multiple corporations in various class action matters alleging recording of calls in violation of the California Invasion of Privacy Act. Negotiated dismissal of them all for a nuisance fee.
Defended a national automobile manufacturer in a putative class action alleging economic damage resulting from repairs to the driver's seat. Plaintiffs voluntarily dismissed their case without payment.

Marissa Ronk represents sophisticated clients in complex commercial litigation and class and mass actions. She is a strategic leader, setting the direction and development of major cases to establish priorities, challenge and frustrate opponents, and create opportunities. Marissa builds case strategies that align with clients’ business goals and values. Rather than react to opponents’ moves, she designs litigation plans that exploit pain points and increase leverage for her clients, whether as a plaintiff or defendant. For example, she often develops counterclaims and pursues aggressive discovery to take an upper hand.
Marissa serves on WTO’s management committee and chairs the firm’s attorney review committee. Prior to joining WTO in 2015, she worked in the litigation department of Winston & Strawn in Chicago.
Credentials
Education
Clerkships
Judicial Clerk to The Honorable William C. Griesbach, U.S. District Court for the Eastern District of Wisconsin
Law Clerk, Department of Justice, Civil Division
Recognition
Chambers USA
Colorado Commercial Litigation, 2026
Benchmark Litigation
Future Star, 2021-2026
40 & Under Hot List, 2023-2026
The Best Lawyers in America
Ones to Watch - Commercial Litigation, 2021-2022, 2024-2025
Ones to Watch - Mass Tort Litigation / Class Actions - Defendants, 2021-2023
Ones to Watch - Product Liability Litigation - Defendants, 2021-2022, 2024-2025
Ones to Watch - Litigation - Labor and Employment, 2024-2025
Colorado Super Lawyers
Super Lawyers, Business Litigation, 2023-2026
Rising Stars, Business Litigation - 2021
Rising Stars, Personal Injury - Products Defense, 2018-2020
Bar and Court Admissions
Colorado
Illinois
Wisconsin
U.S. Court of Appeals, 11th Circuit
U.S. District Court, D. Colorado
U.S. District Court, N.D. Illinois
U.S. District Court, W.D. Wisconsin
Legal Memberships
Colorado Women’s Bar Association Foundation
Board of Directors, present
Leadership Council on Legal Diversity
Mentor, 2022 - present
Fellow, 2022
Colorado General Counsel Mentoring Program
2018-2020
International Association of Defense Counsel
Member
Articles and Presentations
Co-Author, "Trial by Webcam: Tips From a Firsthand Experience," Law360.
Author, "Colorado Supreme Court, following US Supreme Court's ‘Bauman,' Rejects Broad General-Jurisdiction Theory," Washington Legal Foundation's The Legal Pulse.
Co-Author, "The Affordable Care Act and Colorado's Collateral Source Rule," Denver Law Journal.
Presenter, "How to Safely Use AI to Excel in Law," Faculty of Federal Advocates.
Presenter, "Artificial Intelligence Will Be a Litigator's Best Friend," The Trial Network.
Presenter, "How the Plaintiffs' Bar is Moving Away from Reptile Theory Toward Strict Compliance," The Trial Network.
Presenter, "Practical Considerations to the Reasonable Alternative Design Test," In-house counsel.
Presenter, "WTO WILLS: Taking Ownership of Your Career."
Cases
Commercial Litigation
Secured complete indemnification and no future liability for a green energy manufacturer in a supplier dispute involving a recall of the client's products.
Achieved favorable resolution of a multibillion-dollar commercial dispute for an oil and gas company in an asset purchase dispute.
Commercial Litigation
Secured complete indemnification and no future liability for a green energy manufacturer in a supplier dispute involving a recall of the client's products.
Achieved favorable resolution of a multibillion-dollar commercial dispute for an oil and gas company in an asset purchase dispute.
Served as co-counsel to an oil and gas company in an $80 million dispute. During mediation, we helped effect a buyout solution resulting in valuable land rights and resolving the lawsuit for a small fraction of what it would have cost to settle.
Obtained financial and other relief for a manufacturer in business and trade secrets matters.
Recovered all funds claimed in a breach of contract dispute between two Fortune 20 companies.
Represented General Electric Co. in an international arbitration hearing that resulted in a settlement, after the hearing concluded, for more than 90% of our client’s claim.
Class & Mass Actions
Serving as lead national trial counsel to a major U.S. distributor of vaping products in federal multidistrict litigation in California. We are liaison counsel to all of the distributor defendants in the litigation.
After prevailing on a motion to dismiss all of plaintiffs' nationwide class claims, settled all claims individually for a major appliance manufacturer in a class action involving the doors in all of its microwave ovens.
Served as co-counsel in an oil and gas putative class action alleging violation of royalty rights. An early and aggressive discovery strategy persuaded the plaintiff to walk away from the matter.
Won a motion to dismiss with prejudice a putative class action in federal court in California. The plaintiff alleged violations of the Federal Fair Debt Collection Practices Act (FDCPA) and California's Rosenthal Fair Debt Collections Practices Act.
Represented a major Colorado manufacturer in its winning motion to dismiss class action litigation alleging illegal pesticide use.
Defended several manufacturers of high fructose corn syrup in a multimillion dollar dispute in which the plaintiff alleged her consumption of the product caused her diabetes. The Western District of New York dismissed the complaint with prejudice and that dismissal was upheld by the Second Circuit.
Represented multiple corporations in various class action matters alleging recording of calls in violation of the California Invasion of Privacy Act. Negotiated dismissal of them all for a nuisance fee.
Defended a national automobile manufacturer in a putative class action alleging economic damage resulting from repairs to the driver's seat. Plaintiffs voluntarily dismissed their case without payment.



