Today, the use of strategy consultancy in most organizations is not a choice, but a necessity. Strategy consultants have irreplaceable role in the success of organizations. Competency and competency-based management has been considered widely in recent years. Despite this fact, less attention has been paid to competencies of strategy consultants. This study aims to discover the competencies, determine the relative importance of each competency and finally suggest a comprehensive competency model for strategy consultants. So a mixed (qualitative-quantitative) research was conducted. At the first stage (qualitative research) based on the data approach of Glaser grounded theory and through deep interviews with 21 experts in strategy consulting, 25 competencies of strategy consultants were identified. At the second stage (quantitative research), by fuzzy Dematel method, relative importance of these competencies and the relationships between them have been identified and finally a comprehensive model has been presented. Among the important results of this research is that at the level of main categories, personality competencies and at the level of sub-categories, management and organizational knowledge, strategic thinking, mindfulness and leading the leaders are of the highest importance and effectiveness
