| Nicolas Dalby | Lokomotivo | 8-5-1 (1 NC) | Denmark | Nov 22, 2025 |
| Paul Daley (inactive) | Semtex | 2-1-0 | United Kingdom | May 8, 2010 |
| Aisling Daly (inactive) | Ais the Bash | 2-1-0 | Ireland | Oct 24, 2015 |
| Rodrigo Damm (inactive) | | 3-4-0 | Brazil | Jan 3, 2015 |
| Batgerel Danaa (inactive) | Storm | 3-4-0 | Mongolia | Apr 22, 2023 |
| Cindy Dandois (inactive) | Battlecat | 0-1-0 | Belgium | Apr 22, 2017 |
| Jarjis Danho (inactive) | Man Mountain | 1-1-1 | Syria | Apr 10, 2021 |
| Alexandre Dantas (inactive) | Cafe | 0-2-0 | United States | Feb 28, 2003 |
| Mac Danzig (inactive) | | 5-8-0 | United States | Dec 14, 2013 |
| Beneil Dariush | | 17-8-1 | Iran | May 2, 2026 |
| Sean Daugherty (inactive) | | 0-1-0 | Unknown | Mar 11, 1994 |
| Chris Daukaus | | 4-4-0 | United States | Aug 12, 2023 |
| Kyle Daukaus | | 4-5-0 (1 NC) | United States | Jun 14, 2026 |
| Alexis Davis (inactive) | | 8-6-0 | Unknown | Feb 5, 2022 |
| Brandon Davis (inactive) | Killer B | 2-7-0 | United States | Oct 15, 2022 |
| Marcus Davis (inactive) | The Irish Hand Grenade | 9-6-0 | United States | Jan 1, 2011 |
| Mike Davis | Beast Boy | 5-3-0 | United States | Jul 25, 2026 |
| Phil Davis (inactive) | Mr. Wonderful | 9-3-0 (1 NC) | United States | Jan 24, 2015 |
| Rick Davis (inactive) | The Flying Squirrel | 0-1-0 | United States | May 27, 2006 |
| Hakeem Dawodu (inactive) | Mean | 6-4-0 | Canada | Aug 12, 2023 |
| Grant Dawson | KGD | 12-2-1 | United States | May 9, 2026 |
| Jason Day (inactive) | Dooms | 1-2-0 | Canada | Mar 7, 2009 |
| Martin Day (inactive) | The Spartan | 0-4-0 | Japan | Feb 6, 2021 |
| Tom DeBlass (inactive) | | 0-2-0 | Unknown | Nov 10, 2012 |
| Jason DeLucia (inactive) | | 1-2-0 | United States | Nov 19, 1999 |
| Tony DeSouza (inactive) | | 3-3-0 | Peru | Dec 29, 2007 |
| Edwin DeWees (inactive) | Babyface | 0-3-0 | United States | Nov 11, 2006 |
| Carl Deaton | The Anishinaabe Kid | 0-2-0 | United States | Jul 15, 2023 |
| Jose Delano | | 1-0-0 | Brazil | Apr 4, 2026 |
| Jose Delgado | | 4-2-0 | United States | Sep 12, 2026 |
| Rolando Delgado (inactive) | Roli | 1-2-0 | United States | Nov 14, 2009 |
| Ante Delija | Walking Trouble | 1-2-0 | Croatia | Feb 21, 2026 |
| Roland Delorme (inactive) | | 3-3-0 (1 NC) | Canada | Aug 23, 2014 |
| Vanessa Demopoulos | Lil Monster | 5-6-0 | United States | Sep 26, 2026 |
| Chris Dempsey (inactive) | | 1-3-0 | United States | Feb 27, 2016 |
| Benoit Saint Denis | God of War | 9-4-0 | France | Jul 11, 2026 |
| Nick Denis (inactive) | The Ninja of Love | 1-1-0 | Canada | May 5, 2012 |
| Jason Dent (inactive) | Dynamite | 1-3-0 | United States | Nov 21, 2009 |
| Mackenzie Dern | | 12-5-0 | United States | Aug 15, 2026 |
| Robelis Despaigne | The Big Boy | 2-2-0 | Cuba | Sep 19, 2026 |
| Cyrille Diabate (inactive) | The Snake | 4-4-0 | France | Mar 8, 2014 |
| Marc Diakiese | Bonecrusher | 8-7-0 | Congo - Kinshasa | Nov 4, 2023 |
| Blood Diamond (inactive) | | 0-3-0 | Unknown | Sep 9, 2023 |
| Tyler Diamond (inactive) | | 0-1-0 | United States | Jul 6, 2018 |
| Eldo Xavier Dias (inactive) | | 0-1-0 | Unknown | Dec 16, 1994 |
| Hacran Dias (inactive) | Barnabe | 3-5-0 | Brazil | Oct 28, 2017 |
| Luis Felipe Dias | | 1-1-0 | Brazil | Sep 5, 2026 |
| Juan Diaz | Pegajoso | 1-0-0 | Peru | May 16, 2026 |
| Nate Diaz (inactive) | | 16-11-0 | United States | Sep 10, 2022 |
| Nick Diaz | | 7-7-0 (1 NC) | United States | Sep 25, 2021 |
| Ozzy Diaz | | 1-3-0 | United States | Sep 19, 2026 |
| TJ Dillashaw (inactive) | | 13-5-0 | United States | Oct 22, 2022 |
| Jhonata Diniz | | 3-2-0 | Brazil | Oct 11, 2025 |
| Russell Doane (inactive) | | 3-5-0 | United States | Feb 24, 2018 |
| Drew Dober | | 15-11-0 (1 NC) | United States | Mar 7, 2026 |
| AJ Dobson | | 1-3-0 | United States | Mar 23, 2024 |
| Shana Dobson (inactive) | Danger | 2-4-0 | United States | Feb 20, 2021 |
| David Dodd (inactive) | | 0-2-0 | United States | Jun 9, 2000 |
| John Dodson (inactive) | The Magician | 10-7-0 | Unknown | Aug 15, 2020 |
| Joe Doerksen (inactive) | El Dirte | 2-7-0 | Canada | Dec 11, 2010 |
| Roman Dolidze | | 9-6-0 | Georgia | Aug 22, 2026 |
| Cameron Dollar (inactive) | | 0-1-0 | United States | Jun 20, 2009 |
| CB Dollaway (inactive) | The Doberman | 11-9-0 | United States | Sep 15, 2018 |
| Daniil Donchenko | | 4-0-0 | Ukraine | Sep 5, 2026 |
| Cody Donovan (inactive) | Donnybrook | 1-3-0 | Unknown | Jul 19, 2014 |
| Houston Dorr (inactive) | | 0-1-0 | United States | Oct 17, 1997 |
| Stan Dorsainvil | The Drill | 1-0-0 | United States | Aug 22, 2026 |
| Lerryan Douglas | Gunslinger | 1-1-0 | Brazil | Aug 22, 2026 |
| John Dowdy (inactive) | | 0-1-0 | Unknown | Apr 7, 1995 |
| Danny Downes (inactive) | | 0-2-0 | United States | Oct 29, 2011 |
| Derek Downey (inactive) | | 0-1-0 | United States | Feb 7, 2009 |
| Tomasz Drwal (inactive) | Gorilla | 3-3-0 | Poland | Sep 15, 2010 |
| Robert Drysdale (inactive) | | 0-0-0 (1 NC) | United States | Jul 6, 2014 |
| Hugo Duarte (inactive) | | 0-1-0 | Brazil | May 15, 1998 |
| Yuneisy Duben | | 0-2-0 | Venezuela | Jun 6, 2026 |
| Matthieu Duclos | | 1-0-0 | France | Sep 5, 2026 |
| Emily Ducote (inactive) | Gordinha | 2-3-0 | United States | May 18, 2024 |
| Viktoriia Dudakova (inactive) | | 2-2-0 | Russia | Jan 11, 2025 |
| Milana Dudieva (inactive) | | 1-2-0 | Russia | Nov 19, 2016 |
| Todd Duffee (inactive) | | 3-2-0 (1 NC) | United States | Sep 14, 2019 |
| Joe Duffy (inactive) | Irish | 4-4-0 | Ireland | Jul 18, 2020 |
| Alexis Dufresne (inactive) | Sneaky Zebra | 0-2-0 | United States | Jan 3, 2015 |
| Jessamyn Duke (inactive) | The Gun | 1-3-0 | United States | Jul 25, 2015 |
| Islam Dulatov | The Ripper | 1-0-0 | Russia | Jul 19, 2025 |
| Isaac Dulgarian (inactive) | The Midwest Choppa | 2-2-0 | United States | Nov 1, 2025 |
| Kelly Dullanty (inactive) | Psycho | 0-1-0 | United States | Mar 22, 2002 |
| Sedriques Dumas | The Reaper | 3-6-0 (1 NC) | United States | Sep 26, 2026 |
| Norma Dumont | The Immortal | 9-4-0 | Brazil | Sep 26, 2026 |
| Chris Duncan | The Problem | 6-2-0 | United Kingdom | Apr 4, 2026 |
| Christian Leroy Duncan | CLD | 8-2-0 | United Kingdom | Jul 18, 2026 |
| Evan Dunham (inactive) | | 11-9-1 | United States | Jun 6, 2020 |
| Tom Duquesnoy (inactive) | Fire Kid | 2-1-0 | France | Mar 17, 2018 |
| Albert Duraev | | 2-2-0 | Russia | Jul 15, 2023 |
| Reuben Duran (inactive) | | 1-3-0 | United States | Mar 16, 2013 |
| Cody Durden | Custom Made | 7-9-1 | United States | Jul 11, 2026 |
| Luiz Dutra (inactive) | Besouro | 0-2-0 | Brazil | May 30, 2015 |
| Merab Dvalishvili | The Machine | 14-3-0 | Georgia | Dec 6, 2025 |
| David Dvorak | Undertaker | 3-3-0 | Czechia | Jun 10, 2023 |
| Matt Dwyer (inactive) | | 1-3-0 | Canada | Jan 30, 2016 |
| Rolando Dy (inactive) | Dy Incredible | 1-3-0 | Unknown | Jun 23, 2018 |
| Shanelle Dyer | The Nightmare | 2-0-0 | United Kingdom | Aug 22, 2026 |