Alexithymia-a trait associated with difficulties understanding one's own emotions-is theorized to stem from deficits in interoceptive awareness, or the ability to detect, accurately monitor, and regulate internal bodily processes. The present meta-analysis analyzed all studies that empirically examined the relationship between alexithymia and interoceptive awareness. Across 66 independent samples (N = 7,146), alexithymia had a small, negative correlation with interoceptive awareness (r = -.162, p = .001, 95% CI [-.252, -.068]), but additional analyses revealed that the strength and directionality of this association was heavily influenced by the specific interoceptive awareness components measured (e.g., interoceptive accuracy vs. sensibility) and the methods used to measure interoceptive awareness (e.g., objective vs. self-report measures). The strength of this relationship was also moderated by diagnosis of participants such that alexithymia was moderately associated with interoceptive awareness in samples with psychiatric and developmental disorders, but the relationship was nonsignificant in healthy, typically developing samples. Results suggest interoception may represent a shared transdiagnostic vulnerability that underlies atypical emotional processing in a variety of disparate clinical populations but that current operationalization and measurement of interoceptive awareness continues to create confusion and inconsistency in the literature. (PsycINFO Database Record (c) 2019 APA, all rights reserved).