Father Lehne, a priest possessed by Azazel, is named after Fredric Lehne, who played Azazel during the show's second season.
This finale episode is called "Lucifer Rising", which mirrors the title of the season premier, Lazarus Rising (2008).
This is the first episode in the series where the end credits appear as black text on a white background.
When the bells are heard chiming in the convent, the melody they chime is the traditional plainsong melody of 'Dies Irae' the start of a Latin poem that translates as 'Day of Wrath'. This same melody is also used in the opening credits of Stanley Kubrick's film The Shining (1980).
Dean tells Zachariah, "How about this? The suite life of Zach and Cas!" He is referring to the mid-2000's Disney Channel sitcom The Suite Life of Zack & Cody (2005).