"Fresh Blood" is the seventh episode of the paranormal drama Supernatural's third season on The CW, and is the show's fifty-first episode overall. The episode was written by Sera Gamble and directed by Kim Manners; it was first broadcast on November 15, 2007. The narrative follows the series' protagonists Sam and Dean Winchester as they have their final confrontation with hunter Gordon Walker, who has been turned into a vampire.

The third season of Supernatural, an American dark fantasy television series created by Eric Kripke, premiered on October 4, 2007, and concluded on May 15, 2008. Traveling throughout America, protagonists Sam and Dean Winchester use their father's journal to help them carry on the family business—saving people and hunting supernatural creatures. The season begins with the brothers tracking down the demons released from Hell in the previous season finale. They become allies with a demon named Ruby, who claims to know a way to release Dean from his demonic pact—he had sold his soul to a demon and was given a year to live in exchange for Sam's resurrection—and wants to protect them from the new demonic leader Lilith. As Dean's deadline approaches, their efforts are further hindered by Bela Talbot, a professional thief of occult items who is often at odds with the Winchesters.