This systematic review synthesises research on social capital in relation to teachers and teacher professional learning between the years 2004-2019. The review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement, and the Weight of Evidence framework for quality and relevance appraisal. After applying eligibility criteria, 66 empirical items were included in the final review. The review finds that social capital among teachers has been associated with five categories of outcomes: 1) teacher professional development, 2) the implementation of change 3) the introduction of new and beginning teachers, 4) teacher retention and job satisfaction, and 5) improved student achievement. These have in turn been associated with the implicit outcome of promoting educational equity. A synthesis of enablers and barriers to the building of social capital among teachers identifies the pervasive role of organisational structures for moderating the relationship between social capital and these outcomes. Findings indicate that different organisational structures may foster different dimensions of social capital, such as bonding, bridging and linking. More research is needed on the relationship between these dimensions and the organisational structure of schools, to promote the desired outcomes of teacher social capital identified in this review.