John Callaghan has a broad practice, including civil litigation, commercial litigation, administrative issues and regulatory offence work. He appears before all levels of courts and tribunals, including arbitration panels. His expertise is often sought for complex cases and he has been described as "unflappable" in his handling of the myriad of cases in which he is involved. John was elected by the profession as a bencher of the Law Society of Ontario, which governs the legal profession in Ontario. John is a member of the Civil Rules Committee, having been appointed by the Chief Justice of the Ontario Superior Court of Justice. The Committee creates the rules governing court practice. John is co-author of Class Action Law and Practice (Butterworths), the leading class action text in Canada. He has been recognized as a leading counsel by Lexpert®, The Best Lawyers in Canada, Benchmark Canada, Chambers Canada and Chambers Global in areas such as class actions, commercial litigation, and competition. John is a frequent lecturer on the subject of procedure and trial advocacy, and he spent a number of years as an instructor of trial advocacy with the University of Toronto.