Despite extensive research highlighting barriers and facilitators of Business-IT alignment’s social dimension, and the considerable amount of empirical evidence highlighting the organizational benefits of knowledge management practices, their relationship has been minimally explored. Aiming to decrease the research gap, this study asks the following research question: How can knowledge management practices contribute to increased social business- IT alignment? To further explore the relationship between the two concepts, the study consists of a case study design of a large, private Swedish company. Interview data from eight business- and IT management representatives, analyzed through thematic analysis and supported by document analysis has helped identify barriers and mitigators. The findings suggest knowledge management practices can help mitigate the barriers businesses face in attaining social business alignment through activities facilitating knowledge sharing, capture and discovery. The study concludes that a) knowledge exchange and socialization sub-processes can mitigate barriers of social business-IT alignment, b) shared access to knowledge repositories and information communication technologies channels can facilitate short term alignment and c) externalization sub-processes may facilitate improved shared domain knowledge between business and IT organizations.