Mia Mountain was born and raised in  Stockholm, Sweden. She studied acting at the  National Academy of Mime and Acting, Sweden's most prestigious performing arts conservatory.

Besides performing at The Royal Dramatic Theater in Stockholm she has also performed in numerous Punchdrunk productions such as  "Sleep No More" in New York City, "The Drowned Man" in London and  other immersive and cross media productions, including a VR activation for FX's Legion at Comic Con in San Diego. 

Mia had the lead in Levan Akin's feature film "Katinkas Kalas" ("Certain People") for which she received a rising star and best actress nomination at The Stockholm Filmfestival. She  has also been seen as Nahara in NBC's Emerald City,  directed by Tarsem Singh and starring Adria Arjona and Vincent D'Onofrio .

Besides acting Mia also works as a writer and studied at Alma Manusutbildning, one of Sweden's most acclaimed screenwriting programs.