Employee engagement is an emerging topic that has gained considerable attention from human resources professionals and researchers who posit engagement as a key driver of organizational success. Nevertheless, there exist mixed definitions of the construct and ambiguities in its theoretical underpinnings. This confusion in turn presents problems for both the measurement of the construct and its use when implementing and evaluating strategies aimed at building employee engagement. Such disagreements also raise questions about the reliability and validity of extant measures of engagement, and hence their value to both academics and practitioners. To address this issue, this paper critically examines the current approaches to defining and measuring employee engagement and suggests a path forward towards a consensus as to its meaning and measurement.