| Villain | First appearance | Description |
| The White Face Gang | Mystery Men #1 | Gang of thugs led by John Brandes, secretary to Mr. Vander, a banker, who faked his own kidnapping along with Vander and his daughter in order to learn the combination to Vander's safe. |
| The Skull | Mystery Men #14 | Very gaunt leader of a group of foreign saboteurs who destroyed American infrastructure during full moons. |
| Gimp and Moody | Mystery Men #15 | Leaders of the Roof Killers. |
| Blitz | Blue Beetle #4 | One-eyed leader of a spy ring, out to steal a formula for liquid dynamite. Henchmen included the ax-wielding Ax and the Dwarf, a bald little person with a penchant for chanting, "We kill! We kill! Ha, ha!" |
| Big Dix | Mystery Men #16 | Gang leader responsible for the deaths of children from sales of faulty playground equipment to the city. |
| The Sphinx | Mystery Men #18 | Madman bent on destroying the subway system. Disguised himself in a bulletproof metal sphinx suit. Used alias "Mr. Ivan," also disguised himself as Mr. Ivan's sister. |
| The Sky Ruler | Mystery Men #19 | Caped madman who operated from a massive airplane and dropped cars, like bombs, onto the streets below. Sought a smokescreen gas formula. |
| Galgo | Mystery Men #20 | Criminal mastermind who used a gang of thugs dressed as apes in his quest to seize and destroy plans for a lie detection machine. |
| Lora Crofte | Blue Beetle #9 | Murderous leader of counterfeiting ring. |
| Countess Belladonna | Mystery Men #28 | Judge Talmadge lived a double life as Countess Belladonna, seemingly sweet old lady who knitted names in "her" scarf of the people "she" intended to kill with poisoned knitting needles. Also disguised himself as "Dr. Zinn" in a carnival, and wielded a feather fan that opened to reveal a hypnotic death head image that could overcome other people's will. |
| Death | Mystery Men #30 | Dr. Necrow disguised himself as Death, skull-masked and caped flying devil, to kidnap people to serve as slaves in a secret uranium mine underneath the city. |
| The Red Robe | Blue Beetle #14 | Otto Bohm, head of the Nazi Gestapo operation in the U.S., wore a red hood and green skull mask in his quest for a formula to turn water into gasoline. |
| The Yellow Fang | Blue Beetle #14 | The Mikado's deadliest agent, the Yellow Fang is named for the two long curved teeth protruding from his upper teeth. |
| The Eye | Blue Beetle #14 | Disfigured man with yellow skin, who surrounds himself with disfigured henchmen, uses super-hypnotic powers to induce innocent people into murderous rages. |
| The Masked General | Blue Beetle #23 | Kommandant Viltz led the German occupation of Holland, wearing a mask because one of the victims of his favorite torture—pouring hot oil in people's faces—threw the oil in his own face. |
| Gloat and Saturnia | Blue Beetle #34 | Murderous and powerful pair of invaders from Saturn, in a multi-part serial that ran one chapter at a time. |
| The Prophetic Painter | Blue Beetle #35 | Taunts his future murder victims by painting grisly scenes of their deaths, then stages "accidents" just as he painted them. Elaborate scheme by member of the wealthy Dane family to kill off the other heirs. |
| Mr. Moonface | Blue Beetle #40 | Really Mr. Lunar, who left prison and set in motion a mad scheme for revenge on the judge, prosecutor, and witness who sent him to prison. Plan involved decoys whom he drove mad with chemical-laced masks that self-destructed in flames when removed. |
| Spider Spaulding | Blue Beetle #40 | Mob boss with a web tattoo on his left cheek, whose plans always involved a different angle, and was caught thanks to Joan Mason, girl reporter and Blue Beetle's girlfriend. |
| Cyto and Patra | Phantom Lady #13 | Miss Louis, archaeologist, tried to revive an ancient Egyptian mummy—and succeeded, although the mummy Cyto believed Miss Louis resembled exactly Patra, his lover who set him up for murder in ancient Egypt. Cyto then killed Miss Louis, believing her to be the reincarnated Patra. |
| Shady Lady | Blue Beetle #51 | Slinky and deadly leader of a criminal racket. |
| Princess Brunhild | Blue Beetle #51 | Prussian princess stealing corpses and stuffing them with gold in order to smuggle gold to Nazi allies in South America without being caught by customs. |
| The Sphinx | Blue Beetle #56 | Masked sociopath who planned a series of murders of women, calculated to make headlines and establish herself as someone who would stop at nothing, in preparation for a lucrative kidnapping career. Left behind a small sphinx figurine at the scene of her dagger murders, one of them staged spectacularly under the noses of the police. |
| Villain | First appearance | Description |
| Dr. Thunderbolt | Blue Beetle #3 | Forerunner of the Uxerites, alien invaders. |
| Praying-Mantis Man | Blue Beetle #4 | Dr. Hunter Mann, entomologist whose skin has turned green from prolonged exposure to chlorophyll compounds, gained the power to fly, an invulnerable exoskeleton, and the power to paralyze people with his stare, along with the power to control enlarged deadly creatures. |
| The Red Knight | Blue Beetle #5 | |
| Mister Crabb | Blue Beetle #50 | Used advanced machine, the Scorpion. |
| Mentor the Magnificent | Blue Beetle #51 | Powerful robot programmed with the mind of Dr. Jeremiah Clugg, a misanthropic college science teacher also a skilled hypnotist. |
| Magno Man | Blue Beetle #52 | |
| The Eye of Horus | Blue Beetle #54 | Ancient Egyptian entity brought back to life with the power to fire energy bolts and enslave humans, who became hawk-headed creatures, and was defeated when the Blue Beetle learned its true name, composed only of vowels. |
| Villain | First appearance | Description |
| Doctor Alchemy | Showcase #13 | Enemy of the Flash, Dr. Alchemy began to target Kord Industries for their supply of Promethium, the hardest metal known to exist. Alchemy was able to impart the abilities of the Philosopher's Stone to himself with the material and battled Blue Beetle. |
| Chronos | The Atom #3 | Nemesis to the Atom, when the hero retired, Chronos would become one of the Blue Beetle's most frequent combatants. |
| The Masked Marauder | Captain Atom #84 | Count von Streuben was secretly the Masked Marauder, who fought both Ted Kord and Jaime Reyes. |
| The Squids | Blue Beetle #1 | Todd Van III, scion of a wealthy family, defied his father, who thought he would never amount to anything on his own, by secretly forming the Squids, a team of crooks armed with amphibious uniforms dotted with suction cups that allowed them to scale tall buildings. |
| Jarvis Kord | Blue Beetle #2 | The uncle of Ted Kord, who had his nephew work on experiments that he then used as part of his master plan: creating an army of unstoppable robot soldiers to take over the world. |
| Madmen | Blue Beetle #3 | Team of crooks dressed in zany, multicolored clownish suits. |
| The Men of the Mask | Blue Beetle #4 | Cult of bandits based in Mount Mider, in a small Asian island country. |
| Dan Greer | Blue Beetle #4 | Jealous of the professional success of Dan Garret, Greer impersonated Garret in order to excavate the Mountain of Mider for treasure which he intended to keep for himself. |
| Our Man | Blue Beetle #5 | Morose, fatalistic, and delusional sculptor Hugo felt compelled by forces beyond his control to don an armor-plated suit, modeled after one of his own sculptures, to smash images of heroic ideals and was dubbed Our Man by a crowd of hippies. |
| Carapax | Blue Beetle #1 | Long-time professional rival of Dan Garrett, Conrad Carapax undertook a search of Pago Island to learn why Garrett would have risked his life there. After accidentally touching the wrong wire, his mind was transferred into one of the androids there, making him Carapax the Indestructible Man. |
| Firefist | Blue Beetle #1 | Lyle Barnes was a pyrotechnic researcher so badly burned in an explosion that he fashioned a fireproof and fire-creating uniform in order to exact revenge on the firefighters he blamed for failing to save him. |
| Hybrid | New Teen Titans #24 | A villainous variation of the Doom Patrol led by former Patroller Steve Dayton in order to slay Changeling. Blue Beetle was dragged into their conflict when Dayton turned Kord employee Curt Calhoun into one of his agents and fought alongside the Teen Titans. |
| Maxwell Lord | Justice League #1 | Originally perceived as an amoral business tycoon, Lord turned out to be a high-ranking member of Checkmate that purposely maintained the Justice League as inept in an ongoing plot to wipe out metahumans on Earth. When Ted uncovered this, it cost him his life. |
| Catalyst | Blue Beetle #14 | An agent for Klaus Cornelius, head of the world's largest pharmaceutical firm, whose touch can induce the effect of any drug. |
| Overthrow | Blue Beetle #15 | Former Kord employee and Manhunter operative Arnold Daniel Beck used a suit of cybernetic armor to try and destroy the Blue Beetle. |
| Villain | First appearance | Description |
| La Dama | Blue Beetle # 3 | The aunt of Jaime's friend Brenda, Amparo Cardenas is the biggest crime lord in El Paso, Texas, and the closest thing to an archenemy for Jaime. She is well aware of his dual identity and Jaime being well aware of Amparo's dual identity. |
| The Reach | Blue Beetle #12 | An ancient enemy of the Guardians of the Universe and the Controllers, the Reach disperse their scarabs across the universe that bond with lifeforms, turning them into weapons for the alien race. Jaime becomes a target when the combination of magic and the youth's influence on his scarab allow it to break free of its collective. This example has led to several other scarabs becoming independent and upsetting the plans of the Reach. |
| Black Beetle | Booster Gold #5 | Blaming his sister's death on Jaime, Hector bonded with Reach technology taking the name Black Beetle and alias Joshua. Aligned with the Time Stealers, he has become Jaime's nemesis. |
| Bone-Crusher | Blue Beetle #1 | Rompe Huesos is a skull-masked employee of La Dama. He, Brutale, and Coyote were sent to retrieve the scarab from the Brotherhood of Evil. Jaime took the scarab and was soon infused with it to become Blue Beetle. |
| Coyote | Blue Beetle #1 | Coyote is a humanoid coyote who alongside. He, Brutale, and Bone-Crusher were sent by La Dama to retrieve the scarab from the Brotherhood of Evil. He is later killed by La Dama for the group's failure to retrieve the scarab. |
| Doctor Polaris | Justice League of America #17 | Like his predecessor, John Nichol was also fascinated by the field of magnetism. He eventually began to use his powers in ways that the original had never dreamed of. In his strategy to take down the Blue Beetle once and for all, he would make alliances with some notable Blue Beetle villains including La Dama and Black Beetle. |
| Jarvis Kord | Blue Beetle #2 | Uncle of the second Blue Beetle, Jarvis took Jaime under his wing and the latter viewed him as a mentor for some time before discovering that he was only using him to uncover secrets of the scarab technology. |
| Silverback | Blue Beetle #3 | Silverback is a cyborg gorilla who wields big guns and is a veteran member of the Brotherhood of Evil who was disappointed by Phobia, Warp, and Plasmus' attempt to steal the scarab. He later goes after the scarab himself. |
