Daled IV: Planet that revolves only once every planetary year.
Dalmine Sector: Region of space in the Delta Quadrant.
Dalvos Prime: Planet in United Federation of Planets space.
Danula II: -Planet.
           -Site of the Starfleet Academy Marathon where Cadet Jean-Luc Picard won.
Daran V: Planet directly in the path of Yonada ship in 2268.
Davlos III: Planet located on the Klingon border.
Dayos IV: Planet where Kang found one of the Albino's wives.
Decos Prime: -Planet.
             -Site of a United Federation of Planets base.
Dedestris: Planet in the Delta Quadrant.
Deinonychus VII: Planet where U.S.S. Enterprise NCC-1701-D awaited the supply ship
                 U.S.S. Biko NCC-50331.
Delb II: Homeworld of Nellen Tore, assistant to Admiral Norah Satie.
Delinia II: Planet where Transporter Psychoses was first diagnosed.
Delios VII: Planet that was the home to the Karis Tribe.
Delos: Star system containing the planets Ornara and Brekka.
Delos IV: Planet where Commander Doctor Beverly Cheryl Howard Crusher completed internship.
Delphi Ardu: Planet where the last Tkon outpost was located.
Delta IV: Homeworld to the Deltans.
Delta Quadrant: -One quarter of the Milky Way galaxy.
                -Closest point to United Federation of Planets: 40000 light years.
                -In 2371, U.S.S. Voyager NCC-74656 was lost in the Delta Quadrant.
Delta Rana IV: Home of Kevin and Rishon Uxbridge.
Delta Rana star system: -Planetary system.
                        -Location of planet Delta Rana IV.
Delta Vega: Desolate planet with automated lithium mining station.
Deltived Asteroid Belt: Astronomical formation misplaced by Q2.
Deneb II: Planet where Kesla murdered several women.
Deneb IV: -Planet inhabited by Bandi.
          -Locatioon of Farpoint Station.
Deneb V: Planet where Harcourt Fenton Mudd illegally sold all the rights to a Vulcan fuel 
         synthesizer.
Deneva: Planet inested by Denevan Neural Parasites in 2267.
Denius III: Planet where artefacts showed location of planet Iconia.
Denkiri Arm: -One of the spiral-shaped arms that make up the Milky Way galaxy.
             -Located in the Gamma Quadrant.
Denorios Belt: Charged plasma field where the Bajoran Wormhole is located.
Deriben V: Aquiel Uhnari's last posting prior to Realy Station 47.
Derna: -Planetoid.
       -Fourth satellite orbiting Bajor.
       -Location of a Romulan Star Empire hospital during the Dominion war.
Dessica II: Frontier world where Captain Jean-Luc Picard was believed to have been murdered.
Detrian system: Star system where 2 gas giant planet collided in 2369.
Devidia II: Planet whose inhabitants steal neural energies.
Devolin system: Mass of rocks where the hulk of U.S.S. Pegasus NCC-53847 was discovered.
Devron system: -System in Romulan Neutral Zone.
               -Location of the spatial anomaly discovered in 2370.
Dichromic Nebula: -Interstellar gas cloud.
                  -Location of gravimetric distortion.
Dikon Alpha: Class 9 pulsar.
Dimorus: Planet where Gary Mitchell saved the life of Captain James Tiberius Kirk from a
         poison dart thrown by rodent creatures.
Donatu V: -Planet.
          -Site of an inconclusive battle fought with the Klingon Empire.
Dopa system: Planetary system located within the Cardassian Union.
Doraf I: Planet where U.S.S. Enterprise NCC-1701-D was assigned for terraforming.
Dorala system: Region of space in the Alpha Quadrant.
Dorias Cluster: -Region of at least 20 star systems.
                -Bok was sighted there following his escape from prison.
Dorvan V: -Planet near Cardassian border.
          -Ceded by United Federation of Planets.
Dozaria: Class M world with a hot desert-like climate.
Draken IV: -Planet where Romulan N'Vek helped with defection of M'ret.
           -Site of archeological digs.
Drayan II: Class M planet in the Delta Quadrant with several moons.
Draygo IV: -Class M planet.
           -Rejected as a potential home for the Boraalans.
Draylon II: -Class M planet.
            -Site of Skrreea settlement.
Drema IV: -Planet suffering violent geological instabilities.
          -Home to Sarjenka.
Dreon VII: -Planet.
           -Site of a Bajoran colony.
Dulisian IV: Planet that supposedly sent a distress call in 2368.
Durenia IV: -Planet.
            -Destination of U.S.S. Enterprise NCC-1701-D in 2367.
Dyson Sphere: -Gigantic artificial structure designed to completely enclose a star.
              -Discovered in 2294 by U.S.S. Jenolan NCC-2010.
Dytallix-B: Planet owned by the Dytallix Mining Corporation.