Sidney 'Sid' Rourke is the hidden true main antagonist in the 2009 film Harry Brown.
He is portrayed by Liam Cunningham.
Sid is the uncle of Noel Winters, living in the same violent housing estate as both Noel and Harry Brown. Sid runs a local bar and is later revealed to be the one running the operations of Noel and his gang, which includes drugs, guns and prostitution.
After Harry comes to Sid's bar with the injured police officers Alison Frampton and Terry Hicock following a riot at the estate, he realises that Sid is in fact Noel's uncle and is hiding Noel in the basement, so he can avoid being taken into Police custody. Once this is discovered, Harry raises his gun and prepares to kill Noel, but Sid tells him that he can't allow Harry to shoot one of his relatives, despite being fully aware of his crimes. Harry falters due to health problems and Sid swiftly removes Harry's gun before beating him and dragging him upstairs. Sid berates Noel about how crime isn't a "game", which he proceeds to prove to Noel by murdering a badly wounded Hicock via suffocation, stating to Noel "quick and painless".
Sid watchs as Noel kicks Alison and begins strangling her, until Harry reaches for a concealed gun and shoots Noel in the neck, killing him. Sid then pulls out his own gun and shoots Harry, wounding him. However, before he gets the chance to kill him, Sid is targeted by police snipers who were alerted to the scene by Alison prior to her attack. Harry tells Sid to kill him and that his life had already been ruined, and Sid hesitates as he sees two sniper spots on his chest. Finally, Sid points his gun at Harry but is instantly killed by the snipers with three well placed shots to the chest.