Purpose <p>Molar–incisor hypomineralisation (MIH) is a qualitative enamel defect affecting first permanent molars and often incisors, and is associated with increased risks of caries, hypersensitivity, and poor restorative outcomes. Although global prevalence varies, data from Gulf Cooperation Council (GCC) countries remain limited. This systematic review and meta-analysis aimed to estimate the pooled prevalence of MIH among children in the GCC.</p> Methods <p>A comprehensive search of five databases was conducted up to September 2025 and&#xa0;identified studies published between January 2000 and August 2025 reporting MIH prevalence among children in GCC countries with available data. Eligible studies were published in English or Arabic and included healthy children aged 6 years or older. Risk of bias was assessed using a validated prevalence tool. Meta-analysis was conducted using a random-effects model, and heterogeneity was assessed with I² statistics.</p> Results <p>Eighteen studies involving 15,417 children from Saudi Arabia, the United Arab Emirates, and Bahrain met the inclusion criteria, representing approximately 80% of the GCC population. The pooled MIH prevalence was 19.9% (95% CI [15.7–24.9%]), higher than the global average of 13.5%. Across studies, prevalence ranged from 7.57% to 58.46%, with substantial heterogeneity (I² = 97.9%). Meta-analysis of 11 studies showed no statistically significant sex difference in MIH prevalence (pooled OR for females vs males = 0.79, 95% CI [0.59–1.06]; p = 0.12).</p> Conclusions <p>MIH remains an important public health concern, with prevalence in the included GCC countries exceeding international averages in the included GCC countries. Standardised diagnostic criteria and national surveillance systems are strongly recommended to support earlier detection and improved management.</p> <p><b>Registration:</b> INPLASY202390032.</p>