Morgan was briefly engaged to his former Weeds costar, Mary-Louise Parker, in 2008 but the engagement ended in April of that year. Morgan has been in a relationship with actress Hilarie Burton since 2009. The couple welcomed a son, Augustus "Gus", in March 2010.
- Jeffrey has expressed a desire to return to the show since his last appearance in Season 2.
- He is exactly 12 years older than Jensen Ackles, the actor who portrays his character's eldest son, Dean Winchester.
- Jeffrey is the first actor to portray Azazel.
- Jared and Jensen once made a joke about Jeffrey's role as Negan, since Sam and Dean hunt a variety of monsters while Negan struggles with zombies.