Michael Jonas is a minor antagonist in the second season of Star Trek: Voyager, appearing in five episodes.
He was portrayed by Raphael Sbarge.
Michael Jonas was one of the Maquis terrorists who ended up joining Voyager's crew following their own ship's destruction left them stranded in the Delta Quadrant. He was made a crewman and assigned to Engineering. After his fellow engineer and former Maquis Kurt Bendera was killed during a Kazon attack, Jonas attended the memorial service. After the service, Jonas' friend Crewman Hogan tried to get Captain Janeway to offer the Kazons technology in order to prevent further attacks. Hogan later tried to convince B'Elanna Torres to contact their old Maquis crewmate Seska, who had defected to the Kazon-Nistrim sect. Although Jonas stood silently by during the conversations, it was he who decided to act on Hogan's ideas without authorisation. He secretly contacted the Nistrim, presenting himself as a friend of Seska and offering assistance.
Jonas continued to feed information to the Nistrim, giving them information on Voyager's transwarp experiments and on a Cardassian planet killer weapon that had been transported to the Delta Quadrant. He balked when he was asked to sabotage Voyager, insisting on speaking to Seska herself. However, Seska repeated the instruction, intending to take control of Voyager.
Jonas carried out his instructions, sabotaging the warp coils so Voyager would have to go to a system where the Kazon were waiting in ambush for repairs. When Lieutenant Paris left the ship after being relieved of duty for insubordination, Jonas alerted Seska and the Kazon, who captured Paris for information. This caused Neelix to realise there must be a mole on Voyager so Jonas planted evidence implicating Paris. What he didn't know was that Janeway and Tuvok already knew there was a traitor on board and Paris' insubordination was an act to flush out the mole.
As Paris escaped from the Kazon and warning Voyager of both the ambush and Jonas' treachery, Jonas shut himself in engineering with only Neelix for company and tried to sabotage the ship's weapons. He fought with Neelix and tried to kill him but ended up falling into the warp core, perishing.