Chief Petty Officer Carlton "Denny" Dennis was a Human who served as a non-commissioned officer in Starfleet during the 24th century. He had been a long-term member of Starfleet Security, before being posted as the transporter chief of a secured Transporter Facility on Earth.
Dennis was an avid reader and a self-described "buffer buff", who had collected and restored a large number of classic transporters; he found the work to be a solace after the death of his beloved wife Jane. He was fond of butterscotch candy. He suffered from gout and walked with a cane.
In 2381, Dennis was on duty when Ensigns Beckett Mariner, Brad Boimler, D'Vana Tendi, and Sam Rutherford entered his facility, hoping to access its encrypted transporter to board the impounded USS Cerritos and obtain evidence to exonerate Captain Carol Freeman of destroying Pakled Planet. However, they were unable to bring themselves to incapacitate the grandfatherly Dennis. Dennis initially mistook them for Starfleet Academy cadets and gave them a tour, but soon revealed his suspicion that they were actually there to illicitly use his transporter and brandished a phaser at them.
When the ensigns broke down, Dennis admitted that he never intended to fire the phaser, and made soup to comfort them. He sympathized with their plight, noting that he was following Freeman's trial and did not believe the evidence against her, but informed them that he could not beam them to the Cerritos due to interference from a passing verugament swarm. Nevertheless, he inspired Mariner to realize that they could use a replica Phoenix warp ship at the historical Bozeman theme park to reach the Cerritos. Dennis thus agreed to beam them to Montana instead. (LD: "Grounded")
Dennis was voiced by Bobby Moynihan.