Arnold Judas Rimmer, BSc., SSc. (Bronze Swimming Certificate and Silver Swimming Certificate) was once Second Technician aboard the JMC mining ship Red Dwarf. Three million years after his death, Rimmer was brought back as a hologram of himself, and Rimmer's hologram is currently the senior officer of Red Dwarf over a crew of 4.

Neurotic, charmless, cowardly, petty, career-minded yet underachieving, Rimmer was once in charge of Z Shift and over only one other crewmember, Third Technician Dave Lister; everybody else had requested relocation to avoid Rimmer. Rimmer and Lister were begrudging bunkmates and together the pair made up the lowest ranking members on the ship. Rimmer was responsible, through his own ineptitude, for the radiation leak that turned himself and the rest of the 1,169 crew to dust, except for Lister who was in stasis at the time and would remain so for three million years. When Lister came out of stasis to find he is the last human being alive, the computer Holly brought Rimmer back as a soft light hologram to keep Lister sane, despite the fact the pair hated each other.