Ronald "Ronnie" Barlog was a prisoner on HBO's Oz (TV series) in Season 4. He was played by Brian Bloom.

Barlog was arrested for grand theft auto and sentenced to 13 years in prison. When he was brought to Oz, he recognized an old acquaintance, Chris Keller. Barlog got into a love triangle with Keller and his erstwhile lover, Tobias Beecher.

Beecher was Barlog's guide when he stepped into Oz, and the two became close. Keller tried to warn Barlog to stay away from Beecher, but Barlog replied that he had already gotten into a relationship with Beecher.

Later on, when Barlog and Keller were weight training, Keller told him the story of how he was caught and was now serving 88 years for several murders. The two eventually had sex. The next time Beecher approached Barlog for sex, Barlog confessed his betrayal, and that he believed that Keller and he had something special. Beecher was angry, but respected Barlog's decision.

Soon after, Barlog was called to a meeting with FBI Agent Pierce Taylor, who offered Barlog reduced prison time if he testified against Keller on three unsolved murders. Knowing that Beecher was a former lawyer, he consulted him about the offer. Beecher went straight to Keller and told him about Barlog's treachery. Keller didn't believe Beecher at first, but Keller confronted Barlog in a storage room, asking him if he was an informant. Barlog denied it all, and tried to distract Keller with sex. While Barlog performed oral sex upon him, Keller offhandedly confessed to committing the murders because the victims — all young, gay men — reminded him of something within himself that he hated. He then reached for Barlog's head and snapped his neck, killing him.