Fix for my mistaken previous citation:

I believe this qualifies as a civilian, non academy, original Star Trek. Just doing his own thing (we'll ignore he was a bad guy). Note that it says he was a civilian, which means he did not enter the academy.

http://memory-alpha.wikia.com/wiki/Tristan_Adams

"Dr. Tristan Adams was a male Human civilian in the 23rd century. He was a psychologist and director of the Tantalus Penal Colony in 2266.

Starting around 2246, Adams began work that revolutionized prisons and the treatment of prisoners. His theories transformed prisons from cages into clean, decent hospitals for sick minds. Captain James T. Kirk believed Adams' work had done more than the rest of Humanity had done in the previous forty centuries."