["Journal of Organizational Behavior, Volume 47, Issue 4, Page 685-709, May 2026. ", "\nABSTRACT\nIn recent years, there has been a shift from a between‐person, static view of trait affect and stable performance to a within‐person, dynamic view of state affect and episodic performance. However, these dynamic relationships have yet to be summarized. In this preregistered meta‐analysis, we tested Affect Events Theory—a within‐person theoretical framework that discusses how affect relates to job performance—across 123 independent samples, 14 717 individuals, and 127 410 observations to summarize the within‐person associations between affect and job performance over the workday (i.e., a time frame of 24 h or less). Results showed that within‐person positive affect (PA) was associated with higher task performance, higher organizational citizenship behavior (OCB), and lower counterproductive work behavior (CWB); negative affect (NA) was inversely related to these forms of performance. However, there was a lack of homology across within‐ and between‐person levels of analysis: Between‐person effects were consistently larger; indeed, PA and NA's within‐person effect sizes were generally small to moderate, and PA and NA accounted for less than 5% of the variance in each dimension of job performance. Furthermore, temporal moderator analyses demonstrated that affect was consistently associated with task performance over time, whereas associations of affect and discretionary performance were less straightforward. We discuss how these findings extend prior theorizing, focusing on the need to integrate within‐ and between‐person perspectives, the differences in relationships among job performance dimensions, and temporal considerations for these relationships. We conclude by discussing promising directions for future research.\n"]