The school's namesake, the Lyman twins,[6] arrived in the area upon the invitation of Congressman Charles Delemere Haines.

By 1923, it became apparent that the established school houses in the area did not adequately meet the needs of the growing population.

At a board of trustees meeting it was suggested that the cities of Lake Mary, Longwood and Altamonte Springs consolidate and create one school building.

Under this concept, all elementary schools would now incorporate mandatory kindergarten programs and accommodate students in grades K through 5.

That same year, Lake Brantley High School was established with 9th and 10th grade students, using the former Milwee-cum-Lyman "satellite campus" until its permanent facility in Forest City was completed in mid-1973.

[7] As principal from 1963 through 1994, Carlton Henley was primarily responsible for bringing approximately $900,000 in grant money to Lyman High School and Seminole County.

Each student that wishes to "graduate" from The Academy of Engineering must complete a 10-hour internship at a selected site coinciding with their specialization.

Within the Academy of Engineering there are six areas of specialization: Computer Science, JROTC, Mechatronics, Theatre Design and Production, Automotive & Light Repair, and Building Trades and Construction.

In the rest of the students high school career, they continue their specialization while taking other classes in the ECC.

Fall sports offered include football, swimming, golf, girls' volleyball, cross-country, and bowling.

Spring sports offered include baseball, track and field, softball, boys' volleyball, tennis, water polo, and lacrosse.

[9] Lyman is part of a High School Scholastic A unit competing for Florida Federation of Colorguards Circuit and with Winter Guard International.

[citation needed] The Lyman High School Marching Greyhounds have performed at the Walt Disney World Holiday Parade, the Daytona 500, the Macy's Thanksgiving Day Parade, Chick-fil-A Bowl and the Washington DC Cherry Blossom Festival.