Sam James made his first appearance 14 May 2013. He is portrayed by Cornell S. John.
Sam visits Ava unexpectedly when she is expecting Billy Mitchell, with whom she has a date. Ava is shocked to see Sam and he asks if a voice he hears is his son, Dexter. Ava tells Sam to wait outside while she sends Dexter out, then invites Sam in. He explains his father, who abandoned him as a child, has died and he wants to reunite with Dexter, who he abandoned when he was three months old. Ava is angry but Sam blames her, saying she was not intimate with him after Dexter was born. Dexter comes back and Sam introduces himself as Jacob, an old friend of Ava's. Dexter likes "Jacob", thinking he is better suited to Ava than Billy. When Sam leaves, Ava tells him to never return. [[Sam stays overnight at the local bed and breakfast where proprietor Kim Fox takes a liking to him. Sam helps Ian Beale]] with a plumbing problem at his new restaurant and Dexter invites Sam to go for a drink with him. Sam is about to leave, when Ava arrives and angrily tells Sam to leave. Ava's mother Cora Cross calls Sam by his real name and Dexter realises that he is his father, and is angry at Ava for lying to him. Ava and Dexter continue to reject Sam, until eventually Ava realises she is still in love with Sam and they have sex. Dexter is angry to discover this and tells his mother to choose between them. She chooses Dexter and Sam prepares to leave, but when Dexter sees Ava crying, he reluctantly allows Sam to stay. It emerges that Sam requires a kidney transplant. Ava hopes to donate one of hers but is not a match. Dexter decides to take a test to see if he is a match but Ava refuses to let him. He does so anyway and he is a match, but Sam refuses to let him donate. Dexter persuades his father to accept his kidney and they go through the transplant operation. Ava fusses over both of them while they are recovering, and while Dexter is used to Ava's overprotective nature, Sam feels smothered and considers leaving. On Dexter's birthday, Sam invites Dexter's nurse, Laura Sneddon, who tells Ava how long Sam was waiting for a kidney. Ava then finds a letter confirming that Sam has been on a waiting list since before he returned. Ava confronts Sam, realising that he only returned for Dexter's kidney and tells him to leave. He does but tells Dexter that he is coming back after the weekend. Ava tells him he is not returning but refuses to tell him the truth. This begins to anger Dexter and cause him to insult Ava constantly. Eventually Dexter manages to locate Sam and tells him that he wants to live with him and start afresh. Sam tries to persuade Dexter to go back to Walford and live with Ava but Dexter refuses due to Ava not telling him the truth about the real reason on Sam’s departure. Sam assures Dexter that Ava did nothing wrong and confesses that he only came to Walford for a kidney transplant due to failing health and Ava found out when she discovered Sam’s letter from a hospital. Once Dexter learns the truth about Sam and realising why Ava evicted Sam from her house, he punches Sam and tells him he does not deserve Ava. As he leaves, Sam attempts to apologise but Dexter tells Sam that he is no father to him and mentions he never wants to see Sam again. This leaves Sam heartbroken and Dexter scowls at him for the last time before leaving him to go back home to Ava.