This paper explores how a preservice teacher defined, experienced, and transacted with multiple professional communities in becoming a social justice-minded urban English teacher. It extends research on urban teachers and professional communities by arguing that professional community in relation to urban teachers must be informed by sociopolitical understandings of community. The paper undertakes such retheorizing of professional community by drawing upon and combining Wenger's ("Communities of practice: learning, meaning, and identity," Cambridge University Press, New York, 1998) work on communities of practice and Collins' ("Am Sociol Rev" 75:7-30, 2010) conceptualization of community as sociopolitical terrain. Applying this reconceptualized notion of professional community, the paper describes and analyzes how the preservice teacher became increasingly adept at critically analyzing and engaging, creating and transforming, his professional communities to achieve greater justice in urban education.