Heidi Hynden Walch is an American actress. She voices Princess Bubblegum (except at the end of "Mortal Recoil" and in most of the episode "Too Young," when Princess Bubblegum is 13). She has also done voice-acting for ChalkZone as Penny Sanchez, Teen Titans as Starfire, The Batman as Harley Quinn, Generator Rex as Circe, The Secret of Nimh 2, Viridi in Kid Icarus: Uprising, Coco Bandicoot in Crash Team Racing, Summer Hugglemonster in Henry Hugglemonster, Bubble Monkey in Doc Mcstuffins, the English dubs of Gurren Lagann as Nia Teppelin and Lucky Star as Yutaka Kobayakawa, and appeared in the 1993 live-action comedy film Groundhog Day as Debbie the Bride.
- She is referenced in Issue 2 when Marceline is sucked into the Lich's Bag of Holding and lands on the island with Princess Bubblegum. Marceline asks, "Hynden, is that you?", and Princess Bubblegum responds, "No, Marceline, it's me."