William Clayton (born 2007-2008) is the son of Oliver Queen and Samantha Clayton, the step-son of Nyssa al Ghul, the grandson of the late Robert Queen and the late Moira Queen, and the nephew of Thea Queen. After William's kidnapping at the hands of Damien Darhk he and his mother were relocated to an undisclosed location where he adopted the name Matthew.
William was conceived in 2007 following Oliver Queen's affair with Samantha Clayton. Oliver shared the news with his mother, Moira, expressing that he had messed up. Thinking this could potentially ruin Oliver's life, Moira paid the girl one million dollars to pretend she had miscarried and "asked" her to move away to Central City and never to see Oliver again.
Although Samantha took the money, agreed to lie to Oliver, and moved to Central City, it was later revealed that she never cashed Moira's check. She also denied Moira access to her grandson, William; as Samantha believed the latter would be a bad influence on her son.
Meeting his father, Oliver
A year later, William was running through CC Jitters with his action figure and ran into his father, Oliver, unbeknownst to both of them. He dropped it and Oliver went to give William back his figurine of The Flash and he ran to his mother. The sight of him with his mother made Oliver start to mentally connect some dots.
On his way to a sporting event, William and his mother were briefly stopped by Oliver. While his mother was conversing with Oliver, William told her mother to hurry or they'd miss the game. Unknowingly, Oliver managed to get one of William's hairs so that he could run some DNA tests.
Later, while playing with his action figures on his home patio, William and his mother were interrupted by Oliver once again. He was then told to go play with his toys inside the house. Unknown to him, his mother and Oliver got into an argument as Oliver had found out that William was his son.
The following day, William was formally greeted by Oliver, who told him he was an old friend of his mother's. He was asked if it was okay if he visited him once in a while and the two played with his Flash and Captain Cold action figures.
Kidnapped by Malcolm Merlyn and rescued from Damien Darhk
Damien confronted Oliver and Felicity Smoak and demanded that Oliver get out of the race for mayor but Oliver refused. He then got a video on his phone of William. After his mother was told the truth about Oliver's secret identity and the team received the help from Vixen, his action figure was used to try and magically track him. However, he was moved by Darhk to another location before he could be rescued minutes prior to when they arrived.
At Darhk's hideout, William heard the commotion made by Team Arrow as they fought against Darhk and his Ghosts. He ran outside to find Darhk was magically choking the Green Arrow. When Darhk's magic was cut off he saw the Green Arrow begin beating Darhk in anger. William and the Green Arrow spent a moment staring at each other before he left when the police began to arrive. At the SCPD he was reunited with his mother who had his Flash action figure. He told her that he was bored with the Flash and now wanted one of the Green Arrow. She agreed with him that the Green Arrow was indeed amazing, not knowing that the actual Green Arrow was standing not too far off from them. After that Oliver sent him and his mother away to keep them safe, also making a recording that was meant for William to hear on his eighteenth birthday, revealing their relation and his identity as the Green Arrow to his son.
Tracked down and kidnapped by Adrian Chase
William was later tracked down by Adrian Chase at his bus stop who called him by his name William though he said that his name was Matthew. Chase then claimed that he was a friend of Oliver's.
When Chase was arrested, he sent a phone message to Oliver with a video attached of William screaming for help which prompted him to try to free him from custody. However, Chase didn't divulge where he was keeping William.
Relocation to Lian Yu and rescue
Soon after being kidnapped, William was put on a boat that was anchored off the shore of Lian Yu, which Adrian would attempt to use to escape the island. Oliver arrives on the island and begins demanding Adrian for William, but he continues to evade the answer and battles Oliver. Adrian claimed that William was dead, so that he could convince Oliver to kill him, but he didn't give in. Later Adrian escapes the battle and heads to the boat in which William was in, but Oliver quickly chases after him and fights him for William's location. Adrian reveals William from inside the boat and threatens Oliver to kill him for William's safety, but it would mean that Adrian's kill-switch would blow the island up along with everyone on it.
However if Oliver did not kill Adrian, everyone on the island survives, but William doesn't. Oliver shoots Adrian in the leg and secures William who goes to safety in the arms of his now revealed father. Adrian tells Oliver that William now knows who his father really is though is younger than Oliver was when he learned the truth. He explains that it was good because he would now have to live without his mother. Oliver shielded William's view of Adrian as he took a gun and then shot himself in the head. Soon after killing himself, the killswitch was triggered and the two of them look on as a series of explosions are set off all over Lian Yu.
- "Flash vs. Arrow" (mentioned)
- William is a fan of the Flash, as he is seen with a few of his action figures, including posters from Flash Day in his room. Ironic as his father is Green Arrow, a good friend of the Flash.
- After being saved from Damien Darhk by Green Arrow, he states he is over the Flash.
- In the DC comics, Oliver has two sons named Robert Queen II (who was named in honor of his late paternal grandfather) and Connor Hawke. In the Arrowverse, his name is William instead of Robert or Connor. In the Arrowverse, Connor Hawke is the name of John Diggle's potential son in the future.
- In a currently erased timeline, William, along with everyone in Central City, was killed by Vandal Savage using the Staff of Horus in his efforts to kill Carter Hall and Kendra Saunders. However, due to Barry Allen changing the time continuum, this disaster never occurs.
- According to Malcolm Merlyn, William is the person that Oliver loves and cares about most in the world, even more so than Thea and Felicity. This is proven true as he shows how much he cares for him in the season 5 finale Lian Yu in which he goes through great lengths into saving his son from Adrian Chase, like uniting with two of his most hated enemies: Malcolm Merlyn and Slade Wilson in order to save him or when he becomes ruthless against Adrian Chase while asking for his location.
- William owns actions figures of Green Arrow, the Flash and Captain Cold. His favorite is the Green Arrow, whom unknowingly to him is his own father.
- William is the last person to know that his father is Oliver.