John D.S. Gilmour


Phone number
(713) 355-5005

John Gilmour co-chairs the Environmental Litigation section. His practice encompasses significant commercial, tort and environmental matters from coast to coast, including some of the largest contaminated sites in the country.

John represents public and private sector clients in environmental litigation and natural resource damages matters in both state and federal courts across the country. John’s environmental focus predominantly has been contaminated groundwater, surface waterways and mining sites, including river systems degraded from years of industrialization/urbanization; chemical and weapons manufacturing processes; and mining operations. He also handles complex commercial, tort and select IP matters for clients. In every case, John works with the client throughout the representation to determine specific goals, whether it is early settlement, alternative dispute resolution, trial through verdict or other avenues to resolution.

A former multiyear Texas Super Lawyers Rising Star,” John personally enjoys learning as much as possible about each of his client’s businesses and strategic goals in order to better meet their needs and serve their interests. Clients value John’s creative analysis and dispute resolution strategies that consistently result in successful settlements and verdicts. A trusted advisor, John is appreciated for demystifying the litigation process and aggressively defending his client’s rights at every turn, including at trial. He regularly resolves multimillion-dollar disputes by focusing not only on what his client hopes to achieve, but also on what makes sense for them financially.

John began his litigation career clerking for one of the most well-known federal judges in Texas, Judge David Hittner, in the U.S. District Court for the Southern District of Texas. He continues to put his trial skills to good use for his clients nearly two decades later.

I effectively communicate my client’s position with judges, juries and other involved parties in even the most complex matters.”

Representing a Class I railroad in defending against potential cost recovery, contribution and natural resource damages claims arising from three contiguous Superfund sites spanning nearly 300 square miles.

Representing the state of New Jersey as special counsel in pursuing costs and other damages associated with the remediation and restoration of the Passaic River.

Representing the state of New Mexico as special counsel in pursuing costs and other damages associated with the Gold King Mine blowout near Silverton, CO, into the Animas and San Juan Rivers.

Representing the Commonwealth of Puerto Rico related to island-wide groundwater contamination.

Representing a national transportation company concerning the recovery of costs associated with the remediation of the client’s properties against former lessees that released hazardous materials.

Representing an international energy company in a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) contribution action against various potentially responsible parties arising out of a contaminated dump site and salvage yard.

Representing the city of Houston in defending against a citizen suit action under the Clean Water Act arising out of construction projects at Bush Intercontinental Airport.

Representing an international energy company in defense of Superfund litigation and other matters involving claims brought under CERCLA, Resource Conservation and Recovery Act (RCRA) and various common law theories of recovery.

Representing an oil and gas owner and operator in the defense of a groundwater contamination suit.

Representing the largest private port in Texas in litigation bringing claims against a major oil company for fraud and breach of various easements, leases and contracts.

Representing an international telecommunications company in the prosecution of a contract and fraud dispute arising out of the installation of a voice and data system at federal facilities.

Representing 62 members of the U.S. House of Representatives as amicus on a class action against the Federal Emergency Management Agency related to Hurricane Katrina.

Representing a Class I railroad in the recovery of costs and damages arising from derailments.

Representing an oil and gas royalty interest owner in a breach of contract and breach of fiduciary duty dispute.

Representing a chemical manufacturer in the defense of multiple personal injury claims related to an airborne release.

Representing a chemical manufacturer in the defense of personal injury claims arising from an incident on site.

Representing a pipe manufacturer in the defense of multiple toxic tort suits in Texas.

Representing a respirator manufacturer in the defense of multiple toxic tort suits in Texas.

Served as local counsel in various matters, including intellectual property, environmental and commercial litigation, in federal district court in the Southern District of Texas and the Western District of Texas.

Ranked as one of the leading practitioners in the Environmental area by Chambers USA in 2022-2023.

Lawdragon 500 Leading Environmental & Energy Lawyers, 2022-2024.

Recommended in US Legal 500 for his work in the Environment Litigation area, 2019-2023.

Named a Rising Star” by Thomson Reuters for Texas Super Lawyers in 2007, 2008 and 2009.

Houston Bar Association, Environmental Section, board of directors, 2007–2009

Houston Young Lawyers Association, Special Olympics Committee, co-chair, 2007–2008

American Association of Port Authorities, member

Gulf Ports Association of the Americas, member

International Association of Defense Council, former member

Texas Association of Defense Council, former member

Texas Bar Foundation, sustaining life fellow