Jurassic Park will be teaming up with them in the supposed final entry of the Jurassic franchise.
There are so many characters that have been introduced in the franchise and many of them are making a comeback. However, given that it has been several years since the audience saw several characters, there could be a few people who may have forgotten what happened to them in their last appearance.
Dr. Alan Grant
Dr. Alan Grant is one of the most prolific paleontologists in the world at the beginning of Jurassic Park. He's convinced to come to the park to help sign off on it, but a storm hits, and all the dinosaurs break loose. Grant was instrumental in saving Hammond's grandkids and getting everyone off the island.
The character returns to Jurassic Park III when he's tricked into coming to Isla Sorna by the Kirby's. The Kirby's lost their son on the island and they were hoping Grant would help them find him. Grant is very jaded in the film, as he no longer sees the dinosaurs are majestic creatures but as dangerous monsters. However, by the end of the film, he's reminded that they're not all bad.
Dr. Ellie Sattler
One of the most exciting returns in Jurassic World: Dominion is Dr. Ellie Sattler. Dr. Sattler is a paleobotanist who worked with Alan and had a relationship with him. For much of Jurassic Park, the two were split from each other. She helped Hammond and others get the parks systems back online and reunited with Alan just in time to see that his views on children have changed.
Unfortunately, that didn't go anywhere as her next appearance sees that she and Alan did not get married. In fact, she married a man at the State Department and had two kids with him. She also had a small part in Jurassic Park III that mostly consisted of calling the military to get Alan and the others off of Isla Sorna.
Dr. Ian Malcolm
Dr. Ian Malcolm has appeared three times prior to his return in Jurassic World: Dominion. He's a chaotician who warned of the dangers the newly cloned dinosaurs could pose. After being injured in Jurassic Park he returned to The Lost World: Jurassic Park to lead a survey team to the second island and help Hammond convince the world to leave the island alone.
Jurassic World: Fallen Kingdom brought back Dr. Malcolm, but only as a cameo. As the Volcano on Isla Nublar threatened the animals on the island, Ian suggested that the government should let the dinosaurs die. That this was nature's way of righting humankind's wrongs. He also warned that any scenario where humanity and dinosaur are put together is a recipe for disaster.
Owen Grady
Owen Grady (who is one of the bravest characters in the Jurassic franchise). Owen had a relationship with the four velociraptors and was able to train them to do basic commands. Although InGen felt that they could be trained for combat, Owen knew that wasn't going to work out.
After Jurassic World failed, Owen retired to the mountains when Claire returned to ask for his help to save Blue from the volcano. He reluctantly agreed and ended up helping a group of bad guys get ahold of the raptor. Eventually, he was able to free her and Owen ended Jurassic World: Fallen Kingdom by having to reconcile what he had done.
Claire Dearing
Claire Dearing was the operations director of Jurassic World. Audiences first meet her when she was selling investors on their new hybrid dinosaur, the Indominous Rex. Claire's nephews are visiting the island when things start going wrong and she asks for Owen's help to rescue them.
Jurassic World: Fallen Kingdom sees Claire trying to convince the governments of the world to rescue the endangered animals but to no avail. She's approached by one of Hammond's former business partners to save the dinosaurs, but things go wrong once they leave the island. She and Owen save the dinosaurs from being auctioned off and set them free in the world.
Maisie Lockwood
Sir Lockwood, the wealthy former business partner of John Hammond, had a young granddaughter who would constantly get into mischief around the house. She found out that Eli Mills had tricked her grandfather before killing him and he locked her in her room. She was almost killed by the Indo-Raptor before Blue intervened. Maisie is probably one of the best kids introduced in the Jurassic franchise.
The thing about Maisie is that she's actually a clone of Lockwood's dead daughter. The thing that tore a rift between Lockwood and Hammond was that Hammond didn't believe that cloning should be done on people, but in Lockwood's grief, he couldn't resist. She was the one that pushed the button to set the dinosaurs loose and now she's been adopted by Claire and Owen to protect her.
Dr. Henry Wu
Dr. Wu was one of the head geneticists in Jurassic Park and was introduced pretty early in Jurassic Park. He made it to the boat before the hurricane hit and wasn't seen again until Jurassic World, where he created the Indominous Rex. Apparently, he had a plan with InGen to make more hybrid dinosaurs but the film leaves his ultimate goal ambiguous.
Wu also shows up in where it's revealed the Indominous wasn't Wu's first attempt. The kids that were trapped on the island seem to convince him that he's gone down a wrong path but Jurassic World: Fallen Kingdom shows he's just up to his old tricks. The Indo-Raptor was an unstable monster that he tried to make for Mills to sell, but it got loose and Wu wasn't seen again.
Blue
Probably the most famous velociraptor in the franchise, Blue was the leader of the raptor pack in Jurassic World and grew very close to Owen. When the Indominous communicates with the raptor, Blue doesn't know what to do and looks back at Owen, only for all five dinosaurs to get attacked by InGen. However, by the end of the movie Blue helps the Tyranosaurous beat the Indominous, which is one of the best fights in the Jurassic franchise.
Blue was rescued from Isla Nublar in Jurassic World: Fallen Kingdom but not before being shot. She got a blood transfusion from the T. Rex and made a good recovery, just in time to defeat the Indo-Raptor and save the day. She ends the movie free, like the other dinosaurs, and appears to have reproduced somehow in Jurassic World: Dominion.
Lewis Dodgson
One of the most iconic lines in Jurassic Park introduces a character that is far more important than people ever realized. Lewis Dodgson meets Dennis Nedry in Costa Rica and hires him to steal the various Dinosaur embryos for Biosyn, the company that Dodgson works for.
Viral material for Jurassic World: Dominion has revealed that Dodgson is now the CEO of Biosyn, which implies the company will make its first on-screen appearance. With InGen pretty much gone for good, there's no telling what kind of role Biosyn and the returning Dodgson will play.
Barry Sembène
Owen Grady wasn't the only raptor trainer in Jurassic World. Barry Sembène was his partner and friend throughout all of the events. Barry helped lead the charge on the Indominous Rex and when the raptors turned on their trainers he was almost killed. But the end of the movie assured audiences that he was alive.
When the Jurassic World survivors are all at the hanger at the end of the film, Barry is seen helping some people out. He did not return in Jurassic World: Fallen Kingdom but he will return in Jurassic World: Dominion.
