Cozen O’Connor: Riley, Sean J.

Sean J. Riley


Washington, D.C.

(202) 912-4865

(202) 861-1905

Sean J. Riley is a member of Cozen O’Connor’s State Attorneys General Practice group and has significant background handling inquiries for clients before state attorneys general (AGs) in all 50 states. Sean’s litigation, regulatory, and policymaking background has intersected many industries, including pharmaceuticals and health care, environmental and energy, financial services, new and disruptive technologies, gaming, and communications. 

Sean has experience from both sides of the state AG lens. He was a senior executive in a state attorney general’s office from 2009-2015 and in private practice with the government investigations and white collar group of a global law firm advising their pharmaceutical and medical device industry clients on state AG matters.

Immediately prior to joining Cozen O'Connor, Sean served in the Kentucky Attorney General’s office as Chief Deputy Attorney General, the second highest law enforcement official in the state. As Chief Deputy, Sean initiated and managed complex civil litigation and investigatory work on behalf of the Commonwealth of Kentucky that recovered more than $290 million for the public. During his tenure, Sean counseled the state through its involvement in the National Mortgage Settlement of 2012, its renegotiation of the terms of the commonwealth’s participation in the 1998 Tobacco Master Settlement Agreement, and the formation of a first-of-its-kind grant program using settlement proceeds intended to combat the ongoing prescription drug epidemic in Kentucky — the Substance Abuse Treatment Advisory Committee.

Sean was actively involved in the Kentucky Attorney General’s novel and forceful response to the ongoing opioid epidemic in the commonwealth and supervised the office’s active support of Kentucky’s cutting-edge “pill mill” legislation in 2012 known as HB1. He also served as the lead attorney on the office’s efforts to advance its long-stalled litigation against Purdue Pharma, securing a decision from the U.S. Second Circuit Court of Appeals allowing the Attorney General’s fraud case to proceed in Kentucky state courts. Purdue Pharma L.P. v. Kentucky, 704 F.3d 208 (2d Cir. 2013).

From 2012 on, he led the office’s assessment of and response to federal developments in environmental policy, including Kentucky’s position on the EPA’s proposed Clean Power Plan and Waters of the United States rule, as well as many other EPA rules promulgated during the Obama administration. Sean oversaw the Attorney General’s many legal challenges to proposed rules in federal appellate courts around the country, including the U.S. Supreme Court.  

Sean also played a lead role in advising the state during a period of tumultuous health care consolidation in Louisville with the 2012 partnership of University of Louisville Healthcare and KentuckyOne, operated by Catholic Health Initiatives. This innovative transaction involved unique issues of state property law and transactional law, as well as an added layer of complication resulting from the involvement of a private religious organization with the state’s public health care delivery system.

In 2014, Sean counseled Attorney General Jack Conway during the pendency of the companion cases of Bourke v. Beshear and Love v. Beshear, cases that cemented full marriage equality in Kentucky — and nationally — when ultimately consolidated with Obergefell v. Hodges.

Before rising to Chief Deputy, Sean served in various positions in the Kentucky Attorney General’s office, including as special attorney in the Medicaid Fraud Control Unit and as director of the Civil & Environmental Law Division. 

Prior to joining the Kentucky AG’s office, Sean worked in private practice at the law firms of Holland & Knight and Nixon Peabody LLP in Boston where he handled high-profile criminal defense matters and federal criminal investigations for Fortune 500 pharmaceutical and medical device companies. He also defended a federal contractor in both state and federal investigations in the aftermath of the 2006 ceiling collapse in Boston’s “Big Dig” tunnel megaproject.

Sean earned his law degree at Columbia Law School, with a designation as a Harlan Fiske Stone scholar, and his undergraduate degree in Public Policy Studies at Duke University, where he concentrated on health policy, a subject that has remained an enduring interest throughout his legal career.

Prior to law school, Sean worked as the Deputy Finance Director and Assistant Treasurer for then U.S. Senator John Kerry’s 2002 re-election campaign in Massachusetts. In 2010, Sean took a leave of absence from the Kentucky Attorney General’s office to serve as finance director on Attorney General Jack Conway’s campaign for the U.S. Senate. In 2004, 2008, and 2012, Sean was an active volunteer and fundraiser for the presidential campaigns of John Kerry and Barack Obama, and he served as an elected delegate to the DNC from Boston in 2008.

Sean is admitted in D.C., New York, Kentucky, and Massachusetts.



Cozen O’Connor Expands Nationally Recognized State Attorneys General Practice with Addition of Sean J. Riley

December 01, 2015

Riley previously served as chief deputy attorney general in the Kentucky Attorney General’s office and will be resident in Cozen O’Connor’s Washington, D.C., office.


The State AG Report Weekly Update December 10, 2015 [The State AG Report Blog]

December 10, 2015

Antitrust Pennsylvania and District of Columbia Attorneys General and the FTC Challenge Merger of Two Office Supply Companies Pennsylvania AG Kathleen Kane, District of Columbia AG Karl Racine, and the Federal Trade Commission (“FTC”) have sought a preliminary injunction and temporary restraining...

2017 Guide to State Attorneys General [Map]

May 05, 2015

The guide includes information on attorney generals in all 50 states, the District of Columbia, Commonwealth, and Territories of the United States, including a photos, year first elected or appointed, political party affiliation, leadership positions and brief background summaries.

Events & Seminars

Past Events

Health Law 2020

December 04, 2019 - Philadelphia, PA

CTeL Executive Telehealth Fall Summit 2018

December 04, 2018 - Washington, D.C.

CTeL Executive Telehealth Fall Summit 2017

November 30, 2017 - Washington DC


  • Columbia University School of Law, J.D., 2004
  • Duke University, A.B., 1999

Awards & Honors

2013 Best LGBT Attorneys Under 40, National LGBT Bar Association 

2014 Louisville Business First's 40 Under Forty

  • Kentucky
  • Massachusetts
  • New York

Supervised by members of the District of Columbia Bar