Every season of HBO Max's Young Justice introduces new heroes and villains to its diverse lineup of characters. Over the years, the series has given more focus to older characters rather than just the original members of "The Team", as they have all grown into adults since the show's inaugural season. Producers on Young Justice have had the difficult challenge of balancing screen time with so many characters at their dispense, but they have managed and will seemingly continue to bring more characters into the fold.
While there are so many beloved characters in Young Justice, there are also several DC Comics characters who would also fit into the universe of the show
Catwoman
Catwoman is one of the most popular comic book characters DC Comics has ever had, so it's interesting why she has never appeared on the show. While she is primarily a Batman/Bat-Family character, Young Justice has never been shy about including both heroes and villains from that side of the DC Universe. Batman has been a major supporting character in the show since the very beginning along with his former protégés, so including Catwoman in a small role when necessary wouldn't feel out of place by any means.
Ryan Choi (The Atom)
In DC Comics, Ryan Choi is the successor to Ray Palmer as The Atom. He is an intelligent professor who immigrated to the United States from Hong Kong and eventually becomes a superhero in the Justice League. His Atom suit has the same abilities as Palmer's who is already a recurring character on Young Justice. Having another hero as The Atom could be interesting in a guest appearance every once in a while similar to Palmer. Superheroes who can shrink the molecular level have proved to be interesting in past seasons with Palmer and Bumblebee, who have had to physically enter teammates or loved ones to help when a situation called for desperate measures. Choi could add a lot as both a scientist and a hero in the future and just like the other geniuses in the show's universe, he would be right at home.
Crush
Crush, the daughter of Lobo, is one of the newer characters in DC Comics, but she has made an impact since her debut in 2018. Crush has the same physical abilities as her father, despite only being half-Czarnian. In the comics, she spent a lot of time in underground ring fights before being recruited to join the Teen Titans by Damian Wayne. Lobo already exists in Young Justice, appearing on multiple occasions in the third season, so it's not out of the realm of possibility that Crush is somewhere out there already. Lobo is initially unaware of her existence in the comics until she is older, so it would be an easy explanation should she ever appear in the show.
Batwing
Luke Fox also known as Batwing is among the most intelligent members of the Bat-Family in DC Comics, but he has grown a solid reputation since his introduction. As the son of one of Batman's most trusted allies, Lucius Fox, Batwing would be a perfect addition to Young Justice. His armored flight suit, fighting ability, and genius intellect would make him a great fit for either "The Team" or the Outsiders on the show since his age could line up with those of the younger heroes on the show.
Natasha Irons (Steel)
As the niece of superhero John Henry Irons, Natasha Irons is a superhero in DC comics who eventually takes over the mantle of Steel after her uncle gets injured. John Henry has appeared a few times in Young Justice as a member of the Justice League but has never been given any notable dialogue or scenes. Natasha has several connections in the comics to existing Young Justice characters in both the Justice League and on "The Team", so she would fit in naturally. Introducing a version of Natasha could make for fun storylines as fans could get to know one of the lesser-known DC Comics characters, outside of her appearances on The CW's Superman & Lois.
Vixen
Vixen is a prominent member of multiple Justice League lineups past DC animated series' such as Justice League Unlimited, so her absence in Young Justice is notable.
While she wouldn't necessarily need to have a major role in Young Justice, it would be interesting to see her team up with some of the other members of the show in an arc or even just one episode. Young Justice: Phantoms has seen random, but enjoyable team-ups such as Jay Garrick and Rocket who have nothing in common working together, so including Vixen in a similar fashion could prove successful. Her ability to channel the abilities of any animal makes her an asset to any Justice League mission, which has been entertaining to watch in past animated projects.
Jessica Cruz (Green Lantern)
Young Justice has never been afraid of having multiple Green Lanterns appear on the show, as each one brings something new to the table. Jessica Cruz is one of the newer Green Lanterns of Sector 2814 in DC Comics, recently being introduced in 2014. Young Justice has never given a Green Lantern their episode arc or formal story, so giving one to Cruz would be something new the show hasn't done before. With the show leaning into more grownup themes since season three, it would be acceptable to introduce Cruz's character who has a more serious backstory compared to other DC Comics characters. It has recently been revealed that there are four Green Lanterns on the show's Justice League, with the fourth's identity not being currently known, so it is possible that Jessica Cruz is already in the Young Justice universe and fans haven't gotten to see her yet.
John Constantine
Some of Young Justice's most powerful characters include magic users who are masters of the mystical arts. From heroes like Zatanna and Dr. Fate to villains such as Klarion and Child, the show has always spent time on the magical side of the DC Universe. However, one important DC Comics magic-user, John Constantine has yet to appear on the show. Mainly known as a cunning warlock and detective, Constantine usually works with other heroes for his own gain, but he has a more sensitive side towards those he cares about. Often seen working together with Zatanna in the comics and other media, introducing him into Young Justice would serve as an intriguing plot-line for her now that she is an adult and more mature. Young Justice has all the ingredients for introducing their own Justice League Dark team should they choose to go that route, so bringing Constantine into the mix to join the other magic heroes would be amazing.
Starfire
For years people have wanted to see Starfire appear in Young Justice, as she is a longtime fan-favorite member of the Teen Titans and the Justice League. There have been multiple versions of Starfire in other DC animated projects, but Young Justice is somewhere where she would fit in perfectly as a mentor and team leader to some of the younger heroes. Starfire has a long history in the comics and television of being linked to Dick Grayson, who is currently with Barbara Gordon in Young Justice, so it would be a nice change of pace to see her not linked to him romantically for once.
Starfire is an extremely powerful and brave character in the DC Universe and the show would have nothing to lose by adding her in a big role at some point.
Raven
Similar to Starfire, Raven is another major Teen Titans character who has never appeared in Young Justice, despite several other members of that team being main characters in the show. Raven's magic and sorcery offer the unique opportunity to have different storylines including her father Trigon as a villain, or her struggles with controlling her abilities. Raven shares a connection with existing Young Justice characters, Beast Boy, Cyborg, and Wonder Girl among several others, which could be fun to explore. At full strength, Raven is one of the most powerful characters in all of DC Comics and this show is a great place to display her capability. There's an endless amount of possibilities that the producers of Young Justice could do with Raven, so hopefully, fans get to see her in some form eventually.