Debaters and public speakers attend classes in public-speaking skills and forensic theory, and novice and advanced students are eligible to compete in interscholastic regional and international competitions.
Debating and public speaking help boys learn skills of communication, persuasion, logic, critical thinking, research, the use of evidence, and thinking on their feet. Roxbury Latin boys compete among themselves and with students from other schools both in traditional debate formats and in a wide range of public speaking events. Through these competitions, boys gain self-confidence in performing before others and also experience the excitement and exhilaration created by the clash and interplay of competing ideas. In our program, first-year debaters and public speakers attend weekly classes in basic public speaking skills and forensic theory and compete in an interscholastic debating tournament in which boys apply and refine the skills they have learned. After completing the first-year program, boys advance to novice and advanced classes and a wide array of interscholastic competitions.
In 21 of the last 22 years, at least one Roxbury Latin boy has qualified for the World Public Speaking Competition, hosted recently by schools in Germany, Botswana, England, Cyprus, South Africa, Australia, and Lithuania, and Hong Kong.

In 2015-2016, more than 70 boys in Classes I-IV competed in 16 tournaments in New England and Canada, winning many team and individual awards.

Declamations are presented annually on Exelauno Day, and boys compete before the entire School for the David Taggart Clark prizes in Greek and Latin declamation.