| Character | First appearance | Description |
| Dick Grayson | Detective Comics vol. 1, #38 | Serving with Wally West on the Teen Titans, Grayson would become West's best friend and act as best man at his wedding. |
| Iris West | Showcase #4 | A reporter and Barry Allen's girlfriend and eventual wife. |
| Ira West | Flash vol. 1, #134 | Iris's father and Wally's grandfather who is a bit of an absent minded professor. |
| Robert Rudolph West | Flash vol. 1, #116 | Wally's father, Iris's brother and Ira's son. Eventually revealed to be working for the Manhunters. |
| Henry Allen | Flash vol. 1, #126 | Barry Allen's father. He's a doctor. |
| Nora Allen | Flash vol. 1, #126 | Barry Allen's mother. |
| Solovar | Flash vol. 1, #106 | The king of Gorilla City for much of the dealings the Flash had with the culture. |
| Green Lantern | Showcase #22 | Served with the Flash in the JLA where the unlikely pair became best friends. |
| Justice League of America | The Brave and the Bold vol. 1, #28 | Group of costumed heroes that protected the world against some of its worst threats. Barry Allen was a founding member. |
| Elongated Man | Flash vol. 1, #112 | A super hero and ally of the Flash who operated out of Central City. |
| Sue Dibny | Flash vol. 1, #119 | Socialite that dated and later married Elongated Man. |
| Daphne Dean | Flash vol. 1, #126 | An actress that grew up with and dated Barry Allen. |
| Mary West | Flash vol. 1, #133 | The mother of Wally West who moved in with him for a time. |
| Dexter Myles | Flash vol. 1, #138 | Curator of the Flash Museum. |
| Doralla Kon | Flash vol. 1, #145 | An alien from the planet Alkomar that arrived on Earth to learn while there she has super-speed. |
| Teen Titans | The Brave and the Bold vol. 1, #54 | A group that began as a team of sidekicks for the JLA that grew into a home for teen heroes. Wally West was a founding member. |
| Tornado Twins | Adventure Comics #373 | The twin son and daughter of Barry and Iris Allen that became heroes in the 30th century. |
| Character | First appearance | Description |
| Pied Piper | Flash vol. 1, #106 | A longtime member of the Rogues that in wake of Barry Allen's demise became a champion for the poor. |
| Fiona Webb | Flash vol. 1, #285 | A woman that dated and nearly married Barry Allen. On their wedding day, the Reverse-Flash masqueraded as the hero and nearly killed Webb, instead being killed himself by the Flash. Webb would suffer nervous breakdowns afterward at even the mention of Allen's name. |
| Patty Spivot | 5-Star Super-Hero Spectacular | Barry Allen's assistant in the police lab. |
| Matthew Paulson | Flash vol. 1, #273 | A corrupt police chief that was Barry Allen's supervisor prior to Darryl Frye. |
| Darryl Frye | Flash vol. 1, #285 | A police captain for the Central City Police Department and Barry Allen's direct superior. In the New 52, Captain Frye is also Barry's foster father following the death of Barry's mother Nora Allen to which her husband Henry Allen was sent to prison. |
| Frank Curtis | Flash vol. 1, #270 | A detective for the Central City Police Department and Barry Allen's friend. |
| Mack Nathan | Flash vol. 1, #285 | Mack is Barry Allen's African American neighbor and friend. His son Troy Nathan lives with him. |
| Cecile Horton | Flash vol. 1, #332 | Barry Allen's lawyer during his murder trial. |
| Cyborg | DC Comics Presents vol. 1, #26 | A close friend Wally West made from the Teen Titans. |
| Raven | DC Comics Presents vol. 1, #26 | Wally West had a crush on Raven which she used her magic to manipulate him to rejoin the Teen Titans. However, she would begin to have feelings for him which threatened to unleash the evil inside her. |
| Magenta | The New Teen Titans #17 | Wally West's girlfriend while he was Kid Flash, when he learned she could manipulate magnetism he tried to force her into becoming a super-hero. However, it instead pushed her growing mental illness into bipolar disorder. She would often be manipulated into acting as a super-villain and other times take part in destructive behavior on her own. |
| Connie Noleski | Flash Annual vol. 2, #1 | A model that had an on-and-off again relationship with Wally West. She later dated and became engaged to Chunk. |
| Tina McGee | Flash vol. 2, #3 | Scientist that studied Wally West and dated him for a time. She would reunite with her estranged husband and the pair work together for S.T.A.R. Labs. |
| Jerry McGee | Flash vol. 2, #5 | Tina McGee's husband and a scientist researching how to enhance the human body. Performing tests on himself he turned himself into a super-villain that went by Speed McGee and Speed Demon. The Flash helped him get treatment and Jerry reconnected with his wife and the pair work together at S.T.A.R. Labs where they've been known to help the Flash. |
| Red Trinity | Flash vol. 2, #6 | A trio of super-heroes from Russia that formed the service Kapitalist Kouriers in the US. Their predecessor was Blue Trinity. |
| Lady Flash | Flash vol. 2, #7 | Formerly Christina of Blue Trinity, Vandal Savage made the villainess his slave via an addiction to cocaine and gave her a spare Flash costume wherein she took up the title “Lady Flash.” When Savage ordered her to kill the Flash, she refused and joined the hero in taking the villain down. When Christina asked to become the Flash's partner, however, he refused. |
| Chunk | Flash vol. 2, #9 | A scientist that developed a long range teleportation device and, in an accident, merged with it. Forced to absorb mass such that his invention doesn't consume him, Chunk ran afoul of the Flash when these acts caused chaos. With the hero's help, Chunk was able to get his abilities under control, opening a waste removal business, and became a close friend to Wally West. |
| Mason Trollbridge | Flash vol. 2, #15 | Once the sidekick to the vigilante the Clipper, Trollbridge was a neighbor to Wally West in New York, later becoming his friend. At one point, Trollbridge took up the mantle of the Clipper and his son became the super-villain Last Resort. |
| Linda Park | Flash vol. 2, #28 | A reporter that dated and eventually married Wally West. They have two children, Iris and Jai. |
| Character | First appearance | Description |
| Max Mercury | National Comics # 5 | A US Cavalry scout empowered by a Native American shaman with super-speed, the man who would be known as Max Mercury is considered one of the foremost experts in the Speed Force. He bounced through time entering the force, appearing throughout history and mentoring speedsters. |
| Trickster | Flash vol. 1, #113 | One of the Flash's most consistent rogues, the Trickster was brainwashed by the Top and joined the FBI. Trickster would later form a group of reformed Flash rogues to topple his current ranks of enemies until the Top removed his influence. |
| Top | Flash vol. 1, #122 | One of the Flash's rogues, the Top was magically brainwashed by Zatanna into becoming a hero and would briefly be the Flash's partner. Unfortunately, his new programming clashed with his guilt over his past and he lost his mind. The Top would brainwash the Trickster, Pied Piper, and Heat Wave. |
| Heat Wave | Flash vol. 1, #140 | One of the Flash's rogues, Heat Wave was brainwashed by the Top into becoming a hero and worked for Project Cadmus. He would end up at the FBI under the Trickster beside other reformed rogues before the Top removed his influence. |
| Keith Kenyon | Green Lantern vol. 2, #38 | Formerly an enemy of the Green Lantern, Kenyon reformed and became a Union boss in Keystone City. |
| Jesse Quick | Justice Society of America vol. 2, #1 | The daughter of Johnny Quick and Liberty Belle, Jesse for a time acted as the Flash's partner and agreed to be his successor. |
| Argus | Flash Annual vol. 2, #6 | A federal agent that gained super powers, Argus became a hero and ally to the Flash in Central City. |
| Green Lantern | Green Lantern vol. 3, #48 | Serving with Wally West in the JLA, the duo clashed but eventually became good friends. |
| XS | Legionnaires #0 | The granddaughter of Barry Allen and daughter of Dawn Allen of the Tornado Twins. |
| Preston Lindsay | Impulse #1 | The best friend of Bart Allen when he lived in Manchester, Alabama. |
| Carol Bucklen | Impulse #4 | Bart Allen's first love that went to the future with him when Max Mercury was believed dead. |
| Arrowette | Impulse #28 | The daughter of Miss Arrowette, Arrowette was a hero in Manchester where she befriended Bart Allen. |
| Young Justice | Young Justice: The Secret | Largely made up of a new, younger generation of sidekicks to the JLA, Bart Allen was a founding member. |
| Justice Legion Alpha | DC One Million #1 | The premier super hero team of the 853rd century, a time-traveling John Fox became that generation's Flash. |
| Angela Margolin | Flash vol. 2, #143 | The scientist that took over Barry Allen's position in the Central City police department after his absence. She would become romantically involved with the Dark Flash. |
| Fred Chyre | Flash vol. 2, #170 | Detective for the Keystone City police. |
| Jared Morillo | Flash vol. 2, #171 | A detective for the Keystone City police and Fred Chyre's partner for the Department of Metahuman Hostility. After a battle with the villain Cicada, Morillo developed accelerated healing that can seemingly restore him to life from death itself. |
| Gregory Wolfe | Flash: Iron Heights | The warden of Iron Heights that seems to have no tolerance for his inmates and is able to cause pain or comfort in others using his mind. |
| Hunter Zolomon | The Flash: Secret Files & Origins #3 | A talented former profiler for the FBI specializing in super-villains that became an asset for the Keystone City police. After being paralyzed from the waist down by Gorilla Grodd, Zolomon asked the Flash to go back in time and fix the agent's life. Zolomon attempted to use the Cosmic Treadmill to go back in time himself but instead resulted in an accident turning him into the villain Zoom. |
| Peek-a-Boo | Flash vol. 2, #180 | A youth with the power to teleport, Lashawna Baez attempted to use her powers to steal a kidney for her ailing father. While she would be caught and battle the Flash again, she admitted she idolized the hero and wanted to also be a hero. |
| Ashley Zolomon | Flash vol. 2, #197 | The ex-wife of Hunter Zolomon, Ashley blamed herself for his transformation into Zoom. She took his place as the police's profiler in hopes Hunter could one day be rehabilitated. |
| David Singh | Flash Secret Files and Origins #2010 | Barry's CCPD Crime Lab supervisor. |
| James Forrest | Flash Rebirth #2 | Scientist at the Central City Crime Lab. |
| Kristen Kramer | Flash Secret Files and Origins #2010 | Intern at the Central City Crime Lab. |
| Owen Mercer | Identity Crisis # 3 | The son of Captain Boomerang and half brother of Bart Allen, Mercer largely has walked a fine line between hero and villain. He would join the Suicide Squad and helped apprehend the Rogues that killed Bart Allen. |
| Valerie Perez | The Flash: The Fastest Man Alive #1 | The daughter of Manfred Mota, Perez was once saved by Bart Allen and she would dedicate her life to studying the Speed Force. Studying him as an intern at S.T.A.R. Labs, the two would begin a romantic relationship. She would hold him in her arms as he died from his injuries at the hands of the Rogues. |
| The Renegades | Flash vol. 3, #1 | A police task force from the 25th century that believed Barry Allen murdered team member Mirror Monarch. |
| Character | First appearance | Description |
| Henry Allen | The Flash: Pilot | A retired police officer and the father of Barry Allen that was proud of his son Jay, a cop in the motorcycle division, and disappointed in his other son Barry for being a scientist. He often criticized Barry for his reliance on scientific procedure, claiming it didn't compare to actual police work. |
| Jay Allen | The Flash: Pilot | Barry Allen's brother, Jay was a cop for the motorcycle division before his death at the hands of the Dark Riders, the motorcycle gang of Nicholas Pike, prompting Barry to become the Flash. |
| Julio Mendez | The Flash: Pilot | Barry Allen's co-worker in the Police lab. |
| Michael Francis Murphy and Tony Bellows | The Flash: Pilot | Partners for the police force that often appeared as comic relief. |
| Warren Garfield | The Flash: Pilot | Police lieutenant and Barry Allen's boss. |
| Megan Lockhart | The Flash: Watching the Detectives | A private detective that crossed paths with the Flash on occasion and the two shared an attraction. |
| Nightshade | The Flash: Ghost in the Machine | Dr. Desmond Powell, the chief of staff of Central City Hospital and formerly a vigilante in the 50s. |
| Alpha | The Flash: Alpha | An android built by the US government intended to be an assassin but develops a conscience and escapes her masters. Alpha and Flash are forced to face Omega, another android tasked with capturing Alpha. |
| Green Lantern | Justice League of America | Barry Allen's room and teammate in the JLA. |
