Objectives: Neuropsychiatric symptoms (NPS) are highly prevalent in individuals with subjective cognitive decline (SCD) and mild cognitive impairment (MCI), and are strongly linked to accelerated cognitive decline and dementia onset. While mindfulness‐based interventions have shown promise in improving psychological well‐being in clinical and community settings, their efficacy for individuals in these pre‐dementia stages remains unclear. This meta‐analysis examined the effects of mindfulness‐based interventions on NPS and psychological outcomes in these preclinical cohorts. Methods: Eligible studies were retrieved from PubMed, EMBASE, JBI EPB, Web of Science, and Cochrane library. Two independent researchers conducted the literature search and data extraction. Cochrane Risk‐of‐Bias Assessment Tool was used to assess the methodological quality of included studies. Quality of evidence was evaluated using the GRADE approach. Intervention effects were estimated by Hedge's g and 95% confidence interval (CI). Results: A total of 18 randomized controlled trials (including 974 participants from 21 studies) were included in the meta‐analysis. The results demonstrated statistically significant immediate post‐intervention effects of mindfulness‐based interventions on anxiety (g = −0.30, 95% CI −0.49 to −0.11), stress (g = −0.58, 95% CI −0.91 to −0.24), and quality of life (g = 0.50, 95% CI 0.12–0.87). However, no significant effects were found for depression, apathy, mindfulness, and stress‐related biomarkers. Follow‐up data analysis also did not reveal significant effects for depression and anxiety. Conclusions: The findings of this meta‐analysis suggest that mindfulness‐based interventions may improve anxiety, stress, and quality of life in individuals with SCD and MCI. However, more rigorous randomized controlled trials with larger sample sizes and evaluation using physiological parameters are needed to establish more definitive conclusions. Future interventions could consider incorporating cognitive training and health education to address the specific needs of the pre‐dementia population. Registration Number: PROSPERO: CRD42022359906. Key points: Neuropsychiatric symptoms are highly prevalent in individuals with subjective cognitive decline and mild cognitive impairment, and strongly associated with an increased risk of developing dementia.The effectiveness of mindfulness‐based interventions for individuals in the pre‐dementia stages is still uncertain, despite their widespread use in improving psychological well‐being among clinical and community populations.Mindfulness‐based interventions showed immediate beneficial effects on anxiety, stress, and quality of life compared to control treatments.More rigorous and large‐scale randomized controlled trials, evaluated using physiological parameters, are needed to ensure the robustness of study findings and draw definitive conclusions. [ABSTRACT FROM AUTHOR]