This study examines trends in health, well-being, and risk behaviours among high school students in Finnmark, Norway, and compares them with the national average. Data were drawn from the Ungdata survey, covering three waves between 2014 and 2023. The sample included 6,084 high school students in Finnmark and 254,048 students nationwide. MANOVA with polynomial contrasts assessed linear trends among students in Finnmark, and MANOVA with difference contrast tested pairwise differences between Finnmark and national samples. Trend analysis revealed that 26 out of 63 variables, including digital use, school-related variables, antisocial behaviours, and depressive thoughts, increased over time, while 25 variables, such as physical activities, local environment, and bullying remained unchanged. Relationships with parents and substance use improved. Pairwise comparisons showed worse outcomes for Finnmark students in 43 and 41 out of 63 variables across waves, except for substance use and antisocial behaviours. This study indicates limited improvement in health and risk behaviours among high school students in Finnmark. Public health policies tailored to adolescents in Finnmark should focus on mental health services, promoting physical activity, and reducing antisocial behaviours and bullying. Further research should explore Finnmark’s multiethnic context, including the Sámi and Kven populations.