Jake Demari was a Starfleet officer from the 27th century. (Star Trek: Mirror Wars)

Went to Starfleet Academy in 2594, at the age of 18. He graduated in 2598 and served aboard the USS Kelborn under Deker's command as a science officer. He was promoted to lieutenant in 2599, after saving the lives of crewmates in an attack by a Romulan strike force (the Romulan Crisis).

After William Deker left the Kelborn to go to Starfleet Headquarters, Jake stayed as a science officer until 2602, when he was assigned to the USS Majestic as a science officer under the command of James Obeska. He was on the Majestic on her maiden voyage saving the planet Vulcan from the mirror universe invasion fleet. ("Approaching Dawn")