|Portrayed by:||Chad Lindberg|
Despite outward appearances, Ash was brilliant. Having attended MIT, Ash appeared to have built his own computer and wrote computer programs complex enough to access weather satellites looking for demons. Ash was also able to prepare information on how to track Azazel (a.k.a. the Yellow-Eyed Demon) within 51 hours after first meeting the brothers and skimming a year's worth of their father's notes.
Ash speaks very matter of factly when discussing hunt-related information and is held in high esteem among other hunters. He is very laid back and has somewhat of a thick-skin as seen in Everybody Loves a Clown when Dean compares his appearance to that of a Lynyrd Skynyrd roadie.
Ellen Harvelle introduced the boys to Ash after he woke up from his nap, having sprawled out on the top of a pool table. When Jo told the brothers that Ash was a genius, Dean scoffed, saying, "You've got to be kidding me, this guy's no genius, he's a Lynyrd Skynyrd roadie!" To test his wits, Dean challenged Ash to make sense of their father's research. Ash took John's research regarding Azazel and within 2 days time constructed a 'demon alert system' set to track the signs associated with Azazel's appearances.
Later, Ash helped identify Azazel's location from the logo on a bus in Sam's vision. Sam turned to Ash to receive a list of children who are 23 and whose mothers died in a nursery fire, leading him to follow-up on the recently murdered Scott Carey.
As Dean searched for Sam, Ash says that he had some big news he would only tell Dean in person. However, Dean arrived to find the Roadhouse burned to the ground. Ash is presumed dead, based on Dean finding a charred hand with Ash's watch on it. Ellen escaped because she was "out buying pretzels".
After Sam and Dean are killed by two hunters, they wound up in Heaven where Ash, disguised in a Mexican lucha libre style wrestling mask and cape, found them running from Zachariah. He brought them into his little piece of Heaven, which was the Roadhouse freshly stocked with beer. Ash also brought in Pamela to see the brothers. Ash explained that he could move in and out of other people's Heavens by using a practical application of string theory and had now become fluent in Enochian, which was how he found Sam and Dean. Ash and Pamela send them off through a 'shortcut' to a garden where supposedly they were to find a angel named Joshua, who spoke with God.
- Supernatural series creator Eric Kripke stated that Ash's apparent death "had to do with how much I hated the actual Roadhouse itself rather than anyone in it." As for the character's return, Kripke replied, "Ash is a possibility." 
- In Jo's Journal, Ash is referred to as "Miles". This is what he was called in early scripts of Everybody Loves a Clown.
- Ash appears to live at the Roadhouse with Ellen and Jo at which he has his own room. The sign on his door reads "Dr. Badass is" and offers a choice of "in" and probably "out".
- He wears his hair in a mullet style, justifying it as "all business up front; party in the back!"
- Ash unfortunately met his death in ashes, as the Roadhouse was burnt.
- Ash drinks PBR.
- Ash is fluent in Enochian.
- Ash has the capability of moving between people's 'personal heavens'
- ↑ Jo's Journal
- ↑ Bekakos, Liana (April 24, 2008). "Creator Eric Kripke Answers Fan's Questions – Part II. Eclipse Magazine. Retrieved May 25, 2008.