Haley's parents are not fond of him (mostly Claire, but Phil actually appears to really like Dylan) until they hear him play the song he wrote for Haley, titled "In the Moonlight (Do Me)", in front of them, which causes them to think that maybe they were wrong about him. That is, until they hear the chorus. Despite the song's vulgarity, most of the family members afterwards were seen singing the song. When Dylan and Haley got in a fight, he plays the song from his phone in front of her house in a reference to the film Say Anything, and she makes up with him. His band consists of 4 members including him, two other guitarists, and a drummer, all of which (except for the drummer) can be seen playing in the episode "Travels with Scout". Cameron, Haley's uncle, was a drummer in his band for one gig. He and Haley break up early season 2, but are reunited on Valentine's Day. In "Dude Ranch," he proposes to Haley, but is interrupted by Claire. Later, he gets a job as a ranch hand, and he and Haley break up. In the episode "Virgin Territory," Phil accidentally discovers that Dylan had sexual intercourse with Haley, yet this was kept a secret from Phil by Claire, Haley and Alex (who reveals it by accident). In the episode "Disneyland," Haley sees Dylan after Claire points him out, and Dylan is initially embarrassed to see Haley, but later on near the end of the episode they're seen to be back together again, much to Claire's dismay and much to Phil's delight. It was also revealed that he got a job at Disneyland as a Dapper Dan, but was fired. He and Ethan argue about who has Haley.
When Haley is concerned because she might not get into college in Season 4, she decides to live with him in a shared apartment. This makes Phil and Claire mad and they try to persuade her by telling bad things that will happen later if she continues her decision and she becomes confused. But later on, this decision changes when it is revealed that Haley was accepted into college, and that Luke has been hiding the acceptance letter because he doesn't want Haley to leave. Dylan, being a good boyfriend, asks Haley to her school prom that night and asks her to not forget him even while they're apart.
Later on Season 4, it is revealed that Dylan works in a limousine company as a driver.
Apart from appearing frequently during the series, he is labeled as a guest appearance in each episode he is in.
- He likes western films, like "The Gunfighter" ("Great Expectations").
- He likes Anne Hathaway's films ("Moon Landing")
- He is allergic to mayonnaise.
- The only known members of the family who dislike Dylan are Claire and Manny.
- His last name is revealed to be Marshall in "Connection Lost".
- "Come Fly with Me"
- "The Incident"
- "Great Expectations"
- "Fifteen Percent"
- "Moon Landing"
- "My Funky Valentine"
- "Travels with Scout"
- "Airport 2010"
- "Bringing Up Baby"
- "Schooled" (pictured)
- "Arrested" (partly appears in flashback) (pictured)
- "A Slight at the Opera"
- "Heart Broken"
- "Goodnight Gracie" (mentioned only)