Reindeer management (RM) in northern Fennoscandia is an example of social-ecological systems (SESs) providing social, cultural, ecological, and economic values. Changing climate and pasture conditions and societal changes continue to transform the operational environment of RM. These key drivers, and resulting transformations including alternative SES states, have not been studied in detail before. Our comprehensive literature review and interviews with herders reveal that land use, climate change, and governance drive the emergence of SES tipping points. The basis of successful RM depends on the quantity and quality of pastures to secure animal fitness. However, intensive forestry, extreme weather, and predators constrain the availability of forage and suitable calving grounds. Maintaining RM by means of predation compensation mechanisms and regular supplementary winter feeding to adapt to changes brought about by land use and warming climate comprises an alternative system state. However, if negative impacts increase remarkably or rapidly and compensatory mechanisms become insufficient, long-term impacts on system identity, and even local collapses, are expected. Although some environmental and societal changes are perceived as pressures by herders, they can be beneficial for other livelihoods in the region. Therefore, our study raises questions for future studies on social justice, such as who has the right to decide what constitutes a desirable system state, or what collaborative efforts to maintain RM in Fennoscandia would entail. Our work is applicable also in other Arctic/sub-Arctic regions where nature-based livelihoods, such as small-scale forestry and agriculture, hunting, traditional fishing, and gathering are practiced.