Regionally, there has been a lot of focus on the advancement of sustainable arctic industry and circular economy activities within process industry in the Finnish Lapland. In this study, collaboration between university and industry was established facilitated by regional development actors to develop and pilot test a sustainability assessment approach taking into account previous work in this field. The industry partners in this study were a biorefinery investment in the first case and a slag processing service in the second case. As a result of the joint efforts, novel sets of environmental and economic sustainability assessment indicators and associated sub-indicators were developed and the existing set of social indicators was updated. Moreover, environmental and social sustainability assessments were implemented in the biorefinery case accompanied by a separate evaluation of regional economic impacts. In the slag processing case, environmental, economic and social sustainability were assessed. The results of the sustainability assessments indicated very good level of overall performance in both cases. However, specific elements that contributed to lower level of performance included lack of specific sustainability management and reporting approaches and need for better performance in supply chain sustainability, monitoring of greenhouse gas emissions, life cycle thinking and circular economy training. The expected effects of the planned investment on the regional economy were very positive based on the results of the evaluation.