What county is lake mary high school in? United States. Lake Mary High School is a public high school located in Seminole County, Florida, operating under Seminole County Public Schools.What is it like to attend lake mary? Lake Mary offers great academics with many AP classes, and the majority of its teachers are extremely helpful and passionate about their teaching subject. As a senior leaving the school soon, I will miss the sense of outstanding school spirit at Lake Mary.What are the negatives of lake mary high school? One of the few negatives about Lake Mary for me was the school’s drug problem (which is probably similar to many other public high schools in the area, but as I don’t attend those schools, or have social media to learn what happens at other schools, I probably wouldn’t be the most reliable person to comment on this issue).What is the ap participation rate at lake mary high school? The AP® participation rate at Lake Mary High School is 59%. The total minority enrollment is 44%, and 40% of students are economically disadvantaged. Lake Mary High School is 1 of 17 high schools in the Seminole . Lake Mary High School is ranked #2,759 in the National Rankings.