Ryan O'Reily is a fictional character in the television series Oz. He was portrayed by Dean Winters from 1997 to 2003 and in the 2024 short film ZO.
O'Reily is an Irish-American criminal with sociopathic traits, originally sentenced to twelve years to life imprisonment for killing two people while driving under the influence of drugs and alcohol. His sentence was later extended to forty years to life after he confessed to a murder he committed with his brother, Cyril. Before his incarceration, he led the Bridge Street Gang, with Cyril acting as his lieutenant and bodyguard. After Cyril suffers permanent brain damage in a fight, O'Reily embarks on a violent binge of substance abuse.
He is intelligent and manipulative, surviving in Oz by exploiting rivalries among inmates and forming temporary alliances with various prison gangs. The creator of the series, Tom Fontana, compared him to Iago, the antagonist of Shakespeare's Othello.
In the pilot episode, OâÂÂReily bribes guards in solitary confinement to allow Johnny Post to set Dino Ortolani on fire, before betraying Post to the Italians. Later in the season, he attempts to orchestrate Jefferson KeaneâÂÂs death. This plan, however, fails as Keane kills one of his attackers.
OâÂÂReily then partners with Simon Adebisi to murder Nino Schibetta. The two feed him ground glass for several weeks, haemorrhage internally. Upon his death, OâÂÂReily consolidates influence in the prison drug trade. He also supplies Tobias Beecher with heroin, contributing to his addiction and subsequent PCP-induced violent breakdown, during which he blinds Vernon Schillinger in one eye.
OâÂÂReily is diagnosed with breast cancer and undergoes chemotherapy under Dr. Gloria Nathan. He develops romantic feelings for her and arranges for his brother to kill her husband. Cyril is subsequently imprisoned in Oz, where he is sexually assaulted by Schillinger and the Aryan Brotherhood. In exchange for his brother's release, Ryan eventually confesses to orchestrating Preston NathanâÂÂs murder, leading to his own indictment.
OâÂÂReily allies with Beecher and Chris Keller against Schillinger. When SchillingerâÂÂs son Andrew arrives in Oz, he pressures him into buying drugs, and later tortures him for refusing. After Andrew publicly humiliates his father and the Aryan Brotherhood by renouncing beliefs on racial supremacy, Schillinger gives him heroin, resulting in his overdose and death.
OâÂÂReily also develops a friendship with the new CO supervisor, Sean Murphy. During MurphyâÂÂs inmate boxing tournament, OâÂÂReily ensures CyrilâÂÂs victory by drugging his opponents, James Robson, Miguel Alvarez, Chucky Pancamo, and Hamid Khan, with chloral hydrate. He then orchestrates the death of William Cudney, who threatened to expose his actions.
At the end of the season, Oz is forced into lockdown because of racial unrest due to Cyril's defeat of Khan.
OâÂÂReily and Cyril participate in restorative justice sessions with Dr. Nathan and her late husbandâÂÂs parents. She is later assaulted by Patrick Keenan and suspects OâÂÂReily arranged it. He falsely claims responsibility and later kills Keenan. OâÂÂReily also manipulates events leading to the dismissal of Unit Manager Martin Querns, restoring Tim McManus as unit manager.
He also has a dispute with Nikolai Stanislofsky over a contraband cell phone, leading to the latterâÂÂs death at the hands of Officer Claire Howell, with whom OâÂÂReily has a brief sexual relationship. Later, Martin Querns replaces McManus as unit manager and shifts control of Em City toward AdebisiâÂÂs allies. OâÂÂReily and Keller retaliate by murdering Nate Shemin and Mondo Browne and framing Supreme Allah, which results in QuernsâÂÂs dismissal and McManusâÂÂs reinstatement.
In the second half of the season, a television crew comes to film at Oz under journalist Jack Eldridge, who had earlier exposed the OâÂÂReilysâ crimes. Ryan refuses to cooperate with the filming as retribution. Supreme Allah, released from solitary confinement, threatens OâÂÂReily, who then arranges to have him killed by Tug Daniels. Around this time, Suzanne Fitzgerald visits, claiming to be OâÂÂReilyâÂÂs mother. Despite his initial disbelief, he eventually accepts her after confirmation from his father.
Jia Kenmin conspires with Li Chen to target the OâÂÂReilys, leading Cyril to fatally stab Chen during an altercation. Cyril is tried for murder, with his family declining to intervene due to his mental state.
Meanwhile, OâÂÂReily shares a cell with Father Daniel Meehan, who counsels him during CyrilâÂÂs trial. Upon discovering that Glen Shupe had been bribed to lie, OâÂÂReily orchestrates retaliation with the Latinos, ultimately resulting in ShupeâÂÂs mutilation and JiaâÂÂs death at the hands of guards. He then, with Meehan's guidance, begins confronting his childhood trauma and supports CyrilâÂÂs appeal.
OâÂÂReily pressures Shupe to confess, but the testimony fails to aid CyrilâÂÂs defense. Meehan dies of a brain embolism, and OâÂÂReily washes his body in the morgue while reading a passage out of the bible. Rumors then spread that Peter Schibetta cursed OâÂÂReily. He, however, manipulates Chucky Pancamo into believing Schibetta threatened him as well, leading the Italians to murder Schibetta.
CyrilâÂÂs execution is briefly stayed after inmate Jahfree Neema organizes a protest. Despite this, however, Cyril is eventually executed, leaving Ryan devastated. He subsequently begins a romantic relationship with Dr. Nathan.
Later, OâÂÂReily reconciles with his father, Seamus, who expresses remorse after years of neglect. He is last seen accompanying Seamus onto a bus during an attack on Oz.
Critics have described OâÂÂReily as âÂÂthe arch schemerâÂÂ, âÂÂOzâÂÂs resident troublemakerâÂÂ, and "one of the most appealing characters in the show".