Final answer:
The minimum age required to be licensed as a security guard in Ontario is 18 years old, as mandated by the Private Security and Investigative Services Act of 2005.
Step-by-step explanation:
The minimum age to be licensed as a security guard in Ontario is 18 years old. In Ontario, the Private Security and Investigative Services Act of 2005 regulates the security industry, and this includes setting the minimum age for licensure. To become a security guard, applicants must meet several requirements, which include being 18 years of age, completing a training program, and passing a background check.