Jalmari Helander was originally going to direct a comedic sci-fi film "Jerry and Ms Universe" in Canada. When it was postponed due to the COVID-19 pandemic, he quickly wrote Sisu (2022) in the fall of 2021. The film's budget is around $6 million.
The actors by and large insisted on doing their own stunts.
The exteriors are shot in Finnish Lapland, mainly near the villages of Nuorgam and Kaamanen in the Utsjoki municipality.
"Sisu" is a Finnish word described as stoic determination, grit, bravery, resilience, and hardiness.
The film's shooting title was "The Immortal".