Steve "Patch" Johnson is the eldest of the Johnson Children, which include Adrienne and Billy Johnson (Billy is Jack Deveraux Birth Name). Steve was in the merchant marines with Bo, and they were best friends until Steve and Bo got into a fight over a girl named Britta. The Three were friends, and Britta convinced them to all get knife tattoos, but Britta had the tattoo artist hide the location of some secret bonds in the tattoos, unknown to Bo and Steve. Later Bo and Steve both fell in love with Britta, and in a fight Bo knifed out Steve's eye. Steve came to Salem and was on Victor Kiriakis' pay roll and was sent to retrieve some film from Kimberly Brady that she didn't even know she had. The film eventually fell into Melissa and Pete Janning's hands, and the two went on the run when they realized they were in danger. The film eventually led Bo, Hope, Shane, Kimberly, and Victor to Miami, Florida. There Shane gained the evidence he needed to bring down Victor Kiriakis, and Steve was arrested for his part Victor's crimes. However, Victor managed to have himself and Steve freed by blackmailing Larry Welch into taking the fall for everything.
By the end of 1985 Steve had in his care a mysteriously bandaged man he was going to sell to Victor, but the man escaped before the deal went through. In 1986 Steve's old girlfriend Britta Englund returned to Salem, and they soon began seeing each other. However, Britta took a bullet meant for Steve, and after she recovered she quickly left Salem without giving him and explanation. Later that year Steve met and fell in love with Kayla Brady. When Steve began having troubling memories about his past he turned away from Kayla. Later he learned that Adrienne was his sister, and when she murdered their father Duke in self-defense Steve took the blame. Before he was about to be sentenced Adrienne got him off the hook by telling the truth to the court, which she had blocked from her memory. In 1987 Steve tried to help Senator Harper Deveraux by helping him fake his death. Harper was in danger from Victor Kiriakis, who wanted a computer disk Harper came into possession of. Steve agreed to attempt to murder Harper, but Victor's henchman Kai replaced the blanks in Steve's rifle with real bullets. Harper was hit and fell into a coma and Steve went on the run with Kayla. Eventually everything worked out and Steve was exonerated of the charges.
Later that year Steve and sister Adrienne learned that Jack Deveraux was their long lost sibling. Jack was sick with Hodgkin disease so they decided not to confront him with the truth. When Kayla was hired as Jack's nurse Steve saw how much Jack loved Kayla and decided to reject Kayla in hopes she would go to Jack. Steve's rejection worked, and Kayla married Jack. However, Steve kidnapped Kayla from Jack when he learned Harper was trying to poison her. When Kayla eventually recovered she refused to believe she was being poisoned and ran away from him, later to be found by Melissa Anderson Jannings collapsed on the pier. Kayla and Steve began to meet behind Jack's back, and when they were exposed in the papers Jack was humiliated. Jack raped Kayla and had Steve beaten up. Steve and Jack faced off on a rooftop and Jack fell off. Jack was rushed to the hospital but required a kidney transplant. His best chance for a successful match was his brother, and Steve agreed to donate the kidney because their mother Jo asked him. When Kayla recalled that Harper Deveraux was the Riverfront Knifer both she and Kimberly were kidnapped by him. Harper planned to kill them both, but Steve Johnson managed to save them. After Kayla was safe she underwent surgery to repair her hearing. The surgery was a success, but it couldn't restore her speech. Steve proposed to Kayla, and she accepted.
On July 28, 1988 Kayla and Steve wed, and Kayla said "I do" her speech had returned. Steve and Kayla honeymooned in the Orient where they came upon a little deaf boy named Benjy. Benjy was all alone and when his mom couldn't be found they took him in. Steve and Kayla brought Benjy back to Salem and they even considered adopting Benjy but his mother Ellen showed up. Ellen confessed to them that Benjy's father was a dangerous man and to protect him she let them take care of him. Later after their talk Ellen was found dead on the pier. Eventually it came out that Benjy was the son of Stefano DiMera. Benjy's grandfather Orion eventually picked Benjy up and took him where they could live in safety. Later in 1988 Jack Deveraux helped Victor Kiriakis stage a jail break for Harper. Jack was promised a share of Harper's money just as soon as Harper was out of the country. The plan failed, and Harper was shot trying to get to the airport. When Jack took him to the Riverfront Clinic, Harper took Kayla hostage again. Steve managed to save Kayla, and Harper went back to prison.
In 1989 Steve found a badly burnt Nick and agreed to hide him and keep his secret. Steve eventually had to tell Kayla about Nick. After Nick was strong enough he left Steve and Kayla's care and relocated to an old mansion he owned. Unfortunately the mansion only brought bad luck to Nick. An old acquaintance named Eddie was holding Eve hostage there and was looking for some old money of Harper Deveraux's that Nick had hidden there. Steve and Kayla helped Nick try to lure Eddie into a trap but where accused of conspiring to hide stolen money. Eventually Eddie was shot and killed, and as a thank you Nick gave the old mansion to Steve and Kayla.
Steve joined the ISA later in 1989 and his first assignment was to track down an arsonist who had been striking black churches in the south for a number of years. The trail led Steve to the Reverend Saul Taylor's revival camp which had just arrived on the outskirts of Salem. Steve underwent reconstructing surgery to have his eye socket repaired and a glass eye put into it. He then infiltrated the camp as Brother Daniel Lucas while his partner Gail Carson investigated the camp from the outside. Steve learned that Saul Taylor, and his partner Jericho were using the camp as a front to fence stolen goods. They were also responsible for many of the church bombings Steve was sent to investigate and were responsible for the death of his best friend Marcus Hunter's parents. Saul Taylor was eventually shot and killed by his partner Jericho, and Jericho went over a cliff during a fight with his former friend Shane Donovan.
Just when Steve and Kayla soon learned they were expecting, and just when they thought their life had returned to normal Marina Toscano Johnson showed up, claiming to be Steve's wife. Steve was indeed married to her, and believed he had killed her when they got into an argument on a ship and she fell overboard. Marina didn't want Steve back, she just wanted his help in retrieving an old key they had thrown into the sea long ago. Kayla encouraged Steve to help her in hopes she would grant him a divorce, and they all traveled to Italy to retrieve the key. After it was found Steve got into a fight with some of Victor Kiriakis' men, and his glass eye and socket was damaged beyond repair, forcing him to wear his patch again. Back in Salem Kayla confronted Marina for the danger she had put her family in, and they argued in her hotel room. Kayla pushed Marina down and left her very much alive. However when Marina turned up dead in her hotel room Kayla was considered a suspect. Unfortunately Kayla was kidnapped by Victor Kiriakis who wanted the real key Marina had hidden in Steve and Kayla's house.
When Isabella handed over the real key to Victor, Kayla was safely returned to Steve. Kayla was very pregnant at the time, and she and Steve wanted to remarry before the baby's birth. Unfortunately Kayla was arrested during the wedding for the murder of Marina Toscano. Victor Kiriakis had sent Roman II/John Black and Abe a tape on which Kayla threatened to kill Marina, pushed Marina down, and left the room. The tape had been doctored, but Roman II/John was forced to arrest Kayla. Kayla stood trial for the murder of Marina Toscano and was eventually found guilty. Convicted of murder, Kayla was sent to prison. Kayla gave birth to her daughter Stephanie on February 19, 1990 and she allowed Steve to raise the baby. Steve hired a woman named Kelly Parker as the baby's nanny. Unknown to Steve, Kelly was actually a deranged woman named Sheila Salsbury who had lost her baby in birth at the time that Kayla had hers. Sheila, who had become obsessed with the baby, kidnapped Stephanie when Kayla escaped from prison. Kayla and Steve fled the country and followed Sheila to Australia, where they met up with Bo and Hope. With Bo and Hope's help, Kayla and Steve managed to recover their child. When they had learned that Kayla was exonerated of Marina's death, everyone decided to return to Salem.
In 1990 Harper Deveraux escaped from prison and vowed to have his revenge on Steve Johnson. At Steve and Kayla's second wedding, Harper planned to execute Steve from the church bell tower. Jack learned of Harper's plan and stopped him by pushing him to his death from the top of the bell tower. The wedding went on as planned and Steve and Kayla were legally married on August 13, 1990. Steve decided to change his life and become a police officer. While patrolling the harbor late one night, Steve spotted a suspicious looking boat. When he investigated it he found a card that was addressed to Bo Brady and was from Lawrence Alamain. Suddenly the boat exploded. Steve was knocked into a coma, but eventually came around. Because he was a threat to Lawrence, Lawrence had his IV poisoned and Steve died. Before his coffin was buried it was switched with an empty casket.
In 2006, Jack found Steve working as an orderly at a hospital. Jack learned that Steve had amnesia, but convinced Steve to take a DNA test to prove that they were brothers. When the tests came back a match, Steve agreed to go with Jack back to Salem, much to the delight of the Bradys. But, their joy was not fully realized for months as Steve struggled to regain his memory of his life with Kayla. Instead, he tried to start a new life and relationship with Billie Reed.
Viewers learned that Steve had been turned into a DiMera pawn, brainwashed by E.J. DiMera. Under E.J.'s control, Steve committed horrible crimes including kidnapping John Black, assisting in stealing John's kidney, and attempting to murder Shawn Douglas. Kayla fought doggedly for Steve and eventually broke through the brainwashing and Steve began his life over with Kayla. Though, Steve did still pose as a DiMera pawn at times to spy on the DiMeras for the Bradys.
In the summer of 2008, Steve came into contact with a mysterious woman from his past. Ava Vitali, daughter of mob boss Martino Vitali, showed up in Salem to get her life with "Patch" back. Ava held Hope, Steve, Bo, and Kayla hostage and threatened to kill all of them if Steve did not agree to resume their relationship. Eventually, Roman and Abe rescued the quad and Kayla learned that Ava was actually being kept sick through the use of psychological drugs that essentially made her "crazy". When Ava was taken off the drugs, she became a different person and left Steve and Kayla alone.
On May 16, 2008 Kayla gave birth to their second child, a son, named Joseph "Joey" Johnson. While Joey was born prematurely with some problems, he soon recovered and returned home to live with his parents.
Steve started his own business as a Private Investigator. Trent Robins hired Steve to investigate Nick Fallon, but Steve knew that Trent was one who was up to something. Steve continued to investigate Trent, who was Max Brady's biological father. Thanks to Steve, Max was able to find his sister, Melanie.
In February 2009, Kayla was shot in a hostage situation. Steve immediately rushed to her side. Kayla made a full recovery and, though Steve and Kayla remained in Salem, they were not seen on screen again. Eventually, Steve decided to accompany his wife when she decided to leave University Hospital in order to run a free clinic in a third world country. Along with Joey, Steve and Kayla “officially” left Salem in the spring of 2009.
Kayla returned to Salem in the fall of 2011 without Steve. Within a few months, Kayla revealed that she and Steve had been arguing for months. She said that he missed his life of adventure, so he contacted Shane and rejoined the ISA. Kayla and Steve filed for divorce in 2012.