Interoception, the body's perception of its own internal states, is thought to be altered in autism, though results of empirical studies have been inconsistent. The current study systematically reviewed and meta-analyzed the extant literature comparing interoceptive outcomes between autistic (AUT) and neurotypical (NT) individuals, determining which domains of interoception demonstrate robust between-group differences. A three-level Bayesian meta-analysis compared heartbeat counting performance, heartbeat discrimination performance, heartbeat counting confidence ratings, and self-reported interoceptive attention between AUT and NT groups (15 studies; n[subscript AUT] = 467, n[subscript NT] = 478). Autistic participants showed significantly reduced heartbeat counting performance [g = - 0.333, CrI[subscript 95%] (- 0.535, - 0.138)] and higher confidence in their heartbeat counting abilities [g = 0.430, CrI[subscript 95%] (0.123, 0.750)], but groups were equivalent on other meta-analyzed outcomes. Implications for future interoception research in autism are discussed.