Andrianna (Annie) Kastanek is a former federal prosecutor, former Supreme Court clerk, and Co-Chair of Jenner & Block’s Appellate and Supreme Court Practice.
Chambers-ranked in both Appellate law (Band 1, Illinois) and White-Collar Crime & Government Investigations, Annie’s clients call her “smart” and “one of the best lawyers [they] have the pleasure of working with.” One client described Annie’s talent for brief writing as follows: “She knows the judges and knows what will resonate with them… gearing her arguments to her audience.”
Annie has briefed more than 200 federal appeals before the US Courts of Appeals and filed hundreds of briefs in federal district courts. She has argued more than 50 federal appeals, including in the Second, Seventh, and Ninth Circuits. She also handles appeals before the Illinois Supreme Court and intermediate courts of appeals. She has tried 13 cases in federal court, ranging from civil antitrust claims to criminal conspiracy, tax, and fraud charges.
As Co-Chair of the firm’s Appellate and Supreme Court Practice, Annie leverages this vast appellate and trial experience, and her award-winning writing skills, to successfully represent clients in high-stakes matters. She regularly represents clients in the US Supreme Court and the federal courts of appeals, as well as in federal district court. Her areas of extensive appellate experience include criminal law, antitrust, policyholder-side insurance, contractual disputes, class certification, admissibility of expert opinion, and national security and anti-terrorism litigation. She also coordinates closely with the firm’s trial teams on legal and strategic issues, positioning clients for victories on motions to dismiss, motions for summary judgment, and at trial. She is a member of the firm’s Management Committee.
Prior to joining Jenner & Block in 2022, Annie was the Chief of Appeals for the US Attorney’s Office for the Northern District of Illinois. In that role, Annie supervised the office’s criminal appeals and served as a legal advisor to the US Attorney and other prosecutors. Over her 12 years as a federal prosecutor, Annie also served in other leadership positions, including Deputy Chief of Appeals and Civil Rights Coordinator. She received DOJ’s prestigious Director’s Award for Superior Performance of an Appellate Team.
Annie clerked for Justice Anthony M. Kennedy of the US Supreme Court and Judge Kenneth F. Ripple of the Seventh Circuit. She has served as an adjunct law professor at Northwestern Pritzker School of Law, teaching courses on the US Supreme Court.
Representative Matters
- Secured a first-of-its-kind jury verdict in an antitrust case in the Northern District of Illinois. After a six-week trial, the jury found two of the largest egg producers and two industry groups liable for an antitrust violation and returned a multi-million verdict in favor of Annie’s clients.
- Argued in the US Court of Appeals for the Seventh Circuit on behalf of plaintiffs in the Paraquat MDL, challenging the MDL court’s exclusion of the plaintiffs’ general causation expert. Annie’s oral argument is available here.
- Argued in the US Court of Appeals for the Second Circuit on behalf of victims of terrorism, related to a bank’s alleged financing of the Donetsk People's Republic. The Second Circuit, ruling on issues of first impression pertaining to the scope of foreign sovereign immunity, ruled in favor of Annie’s clients. Annie’s oral argument is available here.
- Argued in the US Court of Appeals for the Ninth Circuit for two large food manufacturers, involving FDA regulations governing protein claims on a product’s label. The Ninth Circuit issued a swift and unanimous opinion in favor of Annie’s clients. Annie’s oral argument is available here.
- Argued in the US Court of Appeals for the Seventh Circuit on behalf of a defendant challenging the legal validity of his conviction under the Anti-Kickback Statute. Annie’s oral argument is available here.
- More of Annie’s oral arguments can be accessed here, here, here, and here.
Credentials
Service / Recognition
Overview
Andrianna (Annie) Kastanek is a former federal prosecutor, former Supreme Court clerk, and Co-Chair of Jenner & Block’s Appellate and Supreme Court Practice.
Chambers-ranked in both Appellate law (Band 1, Illinois) and White-Collar Crime & Government Investigations, Annie’s clients call her “smart” and “one of the best lawyers [they] have the pleasure of working with.” One client described Annie’s talent for brief writing as follows: “She knows the judges and knows what will resonate with them… gearing her arguments to her audience.”
Annie has briefed more than 200 federal appeals before the US Courts of Appeals and filed hundreds of briefs in federal district courts. She has argued more than 50 federal appeals, including in the Second, Seventh, and Ninth Circuits. She also handles appeals before the Illinois Supreme Court and intermediate courts of appeals. She has tried 13 cases in federal court, ranging from civil antitrust claims to criminal conspiracy, tax, and fraud charges.
As Co-Chair of the firm’s Appellate and Supreme Court Practice, Annie leverages this vast appellate and trial experience, and her award-winning writing skills, to successfully represent clients in high-stakes matters. She regularly represents clients in the US Supreme Court and the federal courts of appeals, as well as in federal district court. Her areas of extensive appellate experience include criminal law, antitrust, policyholder-side insurance, contractual disputes, class certification, admissibility of expert opinion, and national security and anti-terrorism litigation. She also coordinates closely with the firm’s trial teams on legal and strategic issues, positioning clients for victories on motions to dismiss, motions for summary judgment, and at trial. She is a member of the firm’s Management Committee.
Prior to joining Jenner & Block in 2022, Annie was the Chief of Appeals for the US Attorney’s Office for the Northern District of Illinois. In that role, Annie supervised the office’s criminal appeals and served as a legal advisor to the US Attorney and other prosecutors. Over her 12 years as a federal prosecutor, Annie also served in other leadership positions, including Deputy Chief of Appeals and Civil Rights Coordinator. She received DOJ’s prestigious Director’s Award for Superior Performance of an Appellate Team.
Annie clerked for Justice Anthony M. Kennedy of the US Supreme Court and Judge Kenneth F. Ripple of the Seventh Circuit. She has served as an adjunct law professor at Northwestern Pritzker School of Law, teaching courses on the US Supreme Court.
Areas of Focus
Representative Matters
- Secured a first-of-its-kind jury verdict in an antitrust case in the Northern District of Illinois. After a six-week trial, the jury found two of the largest egg producers and two industry groups liable for an antitrust violation and returned a multi-million verdict in favor of Annie’s clients.
- Argued in the US Court of Appeals for the Seventh Circuit on behalf of plaintiffs in the Paraquat MDL, challenging the MDL court’s exclusion of the plaintiffs’ general causation expert. Annie’s oral argument is available here.
- Argued in the US Court of Appeals for the Second Circuit on behalf of victims of terrorism, related to a bank’s alleged financing of the Donetsk People's Republic. The Second Circuit, ruling on issues of first impression pertaining to the scope of foreign sovereign immunity, ruled in favor of Annie’s clients. Annie’s oral argument is available here.
- Argued in the US Court of Appeals for the Ninth Circuit for two large food manufacturers, involving FDA regulations governing protein claims on a product’s label. The Ninth Circuit issued a swift and unanimous opinion in favor of Annie’s clients. Annie’s oral argument is available here.
- Argued in the US Court of Appeals for the Seventh Circuit on behalf of a defendant challenging the legal validity of his conviction under the Anti-Kickback Statute. Annie’s oral argument is available here.
- More of Annie’s oral arguments can be accessed here, here, here, and here.
Credentials
Admissions
- Illinois, 2005
Education
- Northwestern University Pritzker School of Law, JD, magna cum laude, 2005
- Northwestern University, BA, magna cum laude, 2001
Court Admissions
- US Supreme Court
- US Court of Appeals, First Circuit
- US Court of Appeals, Second Circuit
- US Court of Appeals, Sixth Circuit
- US Court of Appeals, Seventh Circuit
- US Court of Appeals, Ninth Circuit
- US Court of Appeals, District of Columbia Circuit
- US District Court, Northern District of Illinois
Clerkships
- Hon. Anthony M. Kennedy, US Supreme Court
- Hon. Kenneth Ripple, US Court of Appeals, Seventh Circuit
Service / Recognition
Awards
- The American Lawyer, Litigator of the Week, Runner-Up, 2023, 2025
- Chambers USA, Litigation: White-Collar Crime & Government Investigations (Illinois), 2024-2026; Litigation: Appellate (Illinois), 2025-2026
- Crain's Chicago Business, Notable Litigators & Trial Attorneys, 2025
- Forbes’ Best-In-State lawyers, 2025
- Lawdragon 500 Leading Litigators in America, 2025-2026
Community
- Advisory Committee on Circuit Rules, Seventh Circuit