The mindfulness at work literature lacks a multi‐faceted measure of mindfulness that is applicable in the work context. Building on predominantly clinically oriented, multi‐faceted mindfulness measures, we aimed to develop and validate such a measure and to provide first insights into differential validities of mindfulness subfacets for work outcomes. Data from seven work samples (overall n = 4,977) provided support that (a) a 4‐factor structure representing the subfacets of Describing, Nonreactivity, Nonjudging, and Act with Awareness replicates across samples; (b) subfacets and overall scale have good internal consistency and retest reliability; (c) the measure demonstrates convergent and discriminant validity; (d) it demonstrates criterion‐related validity for well‐being, motivational, and interpersonal work outcomes; (e) the Mindfulness@Work Scale explains variance in outcome variables above a unidimensional measures of mindfulness supporting its incremental validity. Furthermore, relative weights and incremental validity analyses revealed differential validities of subfacets of the Mindfulness@Work Scale in relation to positive psychological states versus psychological distress. Overall, findings suggest that the Mindfulness@Work Scale has good psychometric properties and that a differentiation of subfacets provides novel insights into the role of mindfulness for work outcomes.