Background <p>Worry and rumination commonly co-occur and share many features, yet it remains unclear if they share a similar pattern of associations with metacognitive beliefs, and if worry-specific vs. rumination-specific metacognition measures impact the strength of these associations.</p> Methods <p>This meta-analysis examined associations (Pearson’s <i>r</i>) of negative and positive metacognitive beliefs to worry (33 studies, <i>N</i> = 10,600) and rumination (26 studies, <i>N</i> = 9,478).</p> Results <p>Negative and positive beliefs were associated with both worry and rumination, with a similar pattern of associations. Both worry and rumination were more strongly related to negative (<i>r</i> = .651 and 0.535, respectively) than positive metacognitive beliefs (<i>r</i> = .327 and 0.393, respectively). For both worry and rumination, correlations with positive beliefs were stronger in nonclinical than clinical samples, while there was no difference between nonclinical and clinical samples in strength of correlation with negative beliefs. Although associations of negative and positive beliefs to worry and rumination were significant across all metacognitive belief measures, there is some evidence that use of worry-specific vs. rumination-specific measures of metacognitive beliefs may impact the strength of correlation with each thought type.</p> Conclusions <p>Results support conceptualizing metacognitive beliefs as a shared feature of these repetitive negative thought types and suggest metacognitive therapy may be beneficial across thought types.</p>