Is 12 year old a junior?

Yes, a 12-year-old can be considered a junior in certain contexts, such as in school systems where students are categorized by their grade level. In the U.S., a junior typically refers to a high school student in the 11th grade, which usually includes students aged 16-17. However, in some extracurricular activities or sports, younger participants may also be categorized as juniors based on their age group, so context is important.