A person sexually attracted to late-adolescent minors. Not to be confused with (and it invariably will be) a pedophile, who is attracted to prepubescent minors (or hebephile, who is attracted to early adolescent minors). Partly this is because pedophiles like to use this term to defend themselves by deliberately blurring the lines between discussion of pedophilia and issues relating to age of consent.
Very controversial, unsurprisingly, especially when it involves adults and teenagers (teenagers running into age of consent issues in relationships with other teens is a different issue). It should be noted that the term Ephebophilia refers to a preference for late adolescents, so attraction alone does not necessarily make a person an ephebophile. Many people will admit attraction to a teenager or two without acting on it or making a whole lifestyle out of it.
The age of consent varies from country to country and often region by region within a country, which further muddles the issue. However, even in countries where statutory rape laws do not exist or apply only for much younger age groups, some claim the difference is just sophistry. Also, keep in mind there are plenty of teens who can pass for being older, and it's hardly uncommon for people in their 20s to get mistaken for teenagers. Most teenagers in Hollywood are that age anyway.