David Ionis

T 416 956 0117 F 416 598 3730
E dionis@lolg.ca

David is a clear-thinking advocate who thrives when confronting complex issues. He approaches cases with his strong research and writing skills, an impassioned curiosity, and a well-honed attention to detail. 

David is developing a broad litigation practice. Prior to joining Lax O’Sullivan, he summered and articled at a leading Canadian law firm and clerked for the judges of the Court of Appeal for Ontario.

David received his J.D. from Osgoode Hall Law School in 2019, where he graduated in the top 2% of his class and won a host of academic awards, including for placing second overall in his class at the end of first year and top standing in administrative law. David was an avid mooter in law school, placing as a Distinguished Oralist in the Lerners Cup and participating in the Laskin and Wilson Moots. He also volunteered with the Community & Legal Aid Services Program as an Administrative Law Division Caseworker.

Before law school, David worked for the federal government, helping analyze claims for compensation submitted under the Residential Schools Settlement Agreement’s Independent Assessment Process.


  • Called to the Ontario Bar, 2020
  • Clerkship: Court of Appeal for Ontario 
  • J.D., Osgoode Hall Law School, 2019 
  • Honours B.A. (Senate Medal for Outstanding Academic Achievement) in Political Science, with a Minor in Law, Carleton University, 2015