Jon Cieslak represents clients in complex business litigation and white collar criminal defense, focusing on antitrust and competition law claims, prosecutions, and investigations.

He has extensive experience with all manner of civil antitrust claims, including claims under the Sherman Act, California's Cartwright Act, and other state competition laws. Jon has represented clients large and small in litigation asserting both cartel and monopolization claims in a variety of industries, including electronics, manufacturing, travel, media, and the gig economy. He has defended clients in multidistrict litigation, direct purchaser class actions, indirect purchaser class actions, individual actions, and on appeal. Jon also has litigated on behalf of foreign companies in US courts, including disputes involving the Foreign Trade Antitrust Improvements Act (FTAIA).

Jon also has substantial experience as a white collar criminal defense lawyer, in both antitrust and other matters. He has defended companies and C-level executives in price-fixing and bid-rigging prosecutions brought by the US Department of Justice (DOJ). He has represented clients in DOJ investigations involving no poaching claims, and persuaded DOJ to close investigations without charges. In addition, Jon has defended corporate clients in both federal and state courts against a variety of charges, including healthcare fraud, accounting fraud, and money laundering. Jon also routinely assists companies with internal investigations and whistleblower complaints related to antitrust, accounting, healthcare, Foreign Corrupt Practices Act (FCPA), and other issues.

In addition to antitrust litigation, Jon regularly represents clients in other complex business litigation, including claims involving breach of contract, unfair competition, false advertising, Lanham Act, trademark, securities fraud, and trade secret claims.

Jon has always maintained a healthy pro bono practice as well. Among others, he has represented children in immigration custody seeking due process rights, victims of fraudulent mortgage modification services, clients seeking Social Security benefits, and veterans.

Before joining Bona Law, Jon practiced antitrust law, complex business litigation, and white collar criminal defense at Cooley LLP for nearly a decade. He started his legal career as a clerk to the Honorable Jeffrey T. Miller, United States District Judge for the Southern District of California.

Jon has been recognized by Best Lawyers© for his practices in antitrust law, commercial litigation and antitrust litigation.