Currently located in Reisterstown near the intersection of Franklin Boulevard and Reisterstown Road, Franklin High has a long history. It was established in 1820 as the Franklin Academy, a private school. The school went public in 1848, but wasn't completely under public control until 1874. Its name was then changed to Reisterstown High School.
The original Franklin Academy Building was built on Cockeysmill Road, where the Reisterstown branch of the Baltimore County Public Library is now located. In 1905, a new building was built for the high school, leaving the old Academy building to be used for the elementary school. An additional building was built in 1914, and another in 1930 to house the growing student population. Of these three buildings only the 1930 structure still stands on Main Street, currently housing Franklin Middle School. Franklin High School was moved to a more modern building in 1960 about a mile down the road, where it remains to this day. Since 1960, two additions have been built, the most recent in 2000 to deal with the severe overcrowding.
Franklin High School has won the following State Championships:
1949 - Boys Basketball, Class B  MPSSAA Basketball