"Holly Jolly Secrets" is the collective name for the nineteenth and twentieth episodes of the third season of the American animated television series Adventure Time.

In this episode, Finn and Jake stumble across the Ice King’s (voiced by Tom Kenny) video diary and look to uncover his secrets.

The episode was watched by 2.513 million people and received largely positive critical reviews, with the novelist Lev Grossman applauding the exploration of the Ice King's past history.

[3] Originally, Ward's idea for the episode was to do it in the style of Mystery Science Theater 3000, featuring Finn and Jake digging up actual Christmas specials, and having them comment on them.

[3][4] To make up for this last-minute change of plans, the writers had to replace the Christmas programs that Finn and Jake would watch with "the Ice King's odd home movies".

[4][5] During one of the scenes in which the Ice King is bemoaning his situation via video tape, Osborne placed a faux bumper that read "You're watching an Adventure Time Christmas special!

[7][8] Kenny had recorded this version of the song after "It Came from the Nightosphere" aired just for fun, but the crew liked it so much that it eventually made its way into the second part of "Holly Jolly Secrets".

One particular song, titled "Old Cold Footage", that Kiefer composed was supposed to accompany the scene featuring the Ice King's video diary.

Club noted that Finn and Jake finding the Ice King's home tapes led to a "disturbingly intimate holiday special.

"[13] Novelist Lev Grossman, in an interview with NPR praised the backstory of the Ice King and the exploration of his condition, noting that his origin is "psychologically plausible".