Greg Flynn is a deranged former Smallville Deputy Sheriff in the WB TV series Smallville. He served as the main antagonist in the Season 5 episode "Lockdown".
He was portrayed by Kevin Daniels.
Greg Flynn was with the other deputies during the 2005 meteor shower in which they saw the Black Ship and encountered the Disciples of Zod. Greg fought against them with the other officers and was the sole survivor of the massacre. During the attack, Greg's hand was burnt and scarred by the Kryptonians' heat vision.
After the attack, Greg attended therapy but the doctors tried to make it sound like there was no Black Ship or aliens. Greg believed that only Lana Lang and Lex Luthor would be able to explain everything and was determined to prove that he was not insane.
Greg with help from his fiancee Deputy Harris went to the Luthor Mansion and order Lex to evacuate as there has been a bomb threat. Lex was suspicious and when he tried to check his security, the police officers drew guns. Lex made a break for it and his assistant was gunned down while Lex gets into a security room. Flynn managed to cut off communications and identified himself as an ex-cop and wanted to know where the spaceship was.
Flynn revealed he was one of the deputies at the spaceship landing. Lex continued to feign no knowledge of it but Flynn said he'll figure a way to get Lex out of the secure room. Flynn had Harris find Lana and bring her to the mansion in order to get Lex to come out. Lana denied any knowledge of the ship but Flynn remembered her from the crash and Lex had no choice but to come out.
Lex managed to get the drop on the officers and got Lana inside the panic room but Flynn managed to shoot him in the chest. Lex remained protective of her and risked his life to save her, getting shot in the process. Sheriff Adams received a warning of a security alarm at the Luthor Mansion and she calls Harris, who reassured her.
Flynn cranked up the heating elements in the secure room while Lana tends to Lex's wound. Adams was still skeptical and went to the mansion to check it out. She was spotted on the security monitor and Harris went to meet her in the hall. Adams barges into the main room and sees the dead assistant and Flynn, but Harris shoots her from behind.
With Lex mortally wounded, Lana opens the vault and demands they give him help – in return she'll take them to the ship. Flynn agrees and they head out. Meanwhile Clark Kent and Chloe Sullivan sneak into the psychiatry wing and check the tapes of Flynn talking about the spaceship. Lana and the others arrive at the warehouse where Flynn reveals he's going to plant an explosive to draw the police and press, verifying his story. When they get there, the ship is gone but Lana manages to release some pipes and hits Harris.
Flynn drops the bomb while Lana battles Harris and Harris beats Lana. With 34 seconds on the timer, Harris frees Flynn and they plant the bomb before running out. Clark superspeeds in and spots Lana and the bomb. It goes off and Clark makes a last microsecond rescue of Lana just ahead of the explosion. Flynn and Harris are sent flying.
Greg and Harris were later arrested for killing Sheriff Adams with Flynn yelling angrily that Lana knew about the Black Ship.