Thérèse Naess is a trained police officer and lawyer and has extensive experience from security services, international cooperation and business development.

She has worked in managerial positions at the Swedish Security Service in activities that combat terrorism, domestic extremism and organised crime. She has been head of the Swedish Security Service's international cooperation and has been counsellor in Rome. Thérèse Naess has also been head of the Swedish Migration Agency's international cooperation and has been the agency's head of security.

Since 2021, Thérèse Naess has been the head of the National Cyber Security Centre, NCSC.