Sidney Walker is a fictional character from the Australian Seven Network soap opera Home and Away, played by Robert Mammone.

In July 2009, it was announced that a new family, the Walkers, would be introduced to Home and Away on a five-week guest contract.

[5] In June 2010, Mammone revealed that Sid was to find a new romance with an existing character following his return.

[9] He had previously criticised a cancer storyline involving his on-screen son-in-law Romeo Smith (Luke Mitchell) via his Twitter account.

[9] Sid, wife Jody, daughter Indigo and son Dexter move to Summer Bay after Sid finds employment Northern Districts Hospital, covering for Doctor Rachel Armstrong (Amy Mathews) whilst she takes maternity leave.

Sid receives a text message from a woman and Jody reads it, thinking that he is having an affair once again.

Sid protests his innocence, but Jody refuses to listen to him and decides to end their marriage.

Sid helps Indigo's friend Nicole Franklin (Tessa James) as she struggles with the death of Belle Taylor (Jessica Tovey).

In June 2010, Indigo and Dexter arrive at Sid's house, where they reveal that they are not moving to Europe with Jody.

Marilyn Chambers pricks her finger on an old nail and goes to Northern Districts Hospital, where she is apprehensive about meeting Sid after Miles Copeland (Josh Quong Tart) tells her that he dislikes him.

Sid tells Julie that personal matters should not affect professional conduct, but she refuses to listen.

When patient Hayley Doven (Bonnie Sveen) begins to hemorrhage after giving birth, Sid shouts at the nurses to help him and they agree.

When Sid returns home, Nurse Veronica (Sophie Katinis) arrives and they sleep together.

Mitzy reveals that she has cancer, which makes Sid think that she told Marilyn about her prediction so she had someone else to experience dying with.

Mitzy collapses and is rushed to hospital where Sid discovers she has an inoperable brain tumour and may only have weeks to live.

Sid confronts her, convinced that she made up the prediction of Marilyn's death, leaving Mitzy furious.