Business Engagement in Building Healthy Communities is the summary of a workshop convened by the Institute of Medicine’s Roundtable on Population Health Improvement in July 2014 to consider the role of business in improving population health beyond the usual worksite wellness and health promotion activities. The workshop followed previous roundtable discussions on the importance of applying a health lens to decision making in non-health sectors and the need for cross-sector collaborations to advance population health. Invited speakers included representatives from several businesses that have taken action to improve the health of their communities and representatives of business coalitions on health. The workshop was designed to discuss why engaging in population health improvement is good for business; explore how businesses can be effective key leaders in improving the health of communities; and discuss ways in which businesses can engage in population health improvement. This report is a record of the presentations and discussion of the event