This research is motivated by the high intensity of Instagram use among Generation Z, which has triggered widespread exposure to unrealistic beauty standards and increased pressure on physical appearance. The focus of this research problem is to examine the relationship between maladaptive metacognitive beliefs and body image evaluations in this user group. Using a quantitative approach with a correlational design, the research's key stages were systematically carried out by selecting subjects using a purposive sampling technique, administering a 5-Likert-scale questionnaire using the MPAQ and MBSRQ-AS instruments, and testing residual data using the SPSS program. A total of 365 active Instagram respondents aged 18 to 29 in Indonesia were proactively involved as research participants. Research findings based on the Pearson correlation coefficient indicate a significant negative relationship between metacognitive beliefs and the subjects' body image (r = –0.173; p = 0.001). This statistic reflects that the higher a person's tendency for maladaptive metacognitive beliefs, the lower their perceived body image satisfaction. The main conclusion confirms that maladaptive internal metacognitive processes contribute to lower positive body perceptions. However, the strength of this relationship is classified as very weak, indicating a strong dominance of other external variables such as social comparison, self-esteem, and overall visual media exposure. ABSTRAK Penelitian ini dilatarbelakangi oleh tingginya intensitas penggunaan Instagram di kalangan Generasi Z yang memicu maraknya paparan standar kecantikan tidak realistis serta peningkatan tekanan penampilan fisik. Fokus masalah dalam riset ini adalah menguji hubungan antara metacognitive beliefs maladaptif dengan evaluasi body image pada kelompok pengguna tersebut. Menggunakan pendekatan kuantitatif dengan desain korelasional, tahapan penting penelitian dijalankan secara sistematis melalui penentuan subjek menggunakan teknik purposive sampling, pemberian kuesioner berskala 5 Likert memanfaatkan instrumen MPAQ dan MBSRQ-AS, serta pengujian residual data melalui bantuan program SPSS. Sebanyak 365 responden aktif Instagram berusia 18 hingga 29 tahun di Indonesia dilibatkan secara proaktif sebagai partisipan penelitian. Temuan penelitian berbasis koefisien korelasi Pearson menunjukkan adanya relasi negatif yang signifikan antara metacognitive beliefs dengan body image subjek secara nyata (r = –0,173; p = 0,001). Angka statistik ini merefleksikan bahwa semakin tinggi kecenderungan keyakinan metakognitif maladaptif seseorang, maka semakin rendah kepuasan citra tubuh yang dirasakannya. Simpulan utama menegaskan bahwa proses metakognisi internal yang tidak adaptif berkontribusi menurunkan persepsi tubuh positif. Walaupun demikian, kekuatan hubungan ini diklasifikasikan sangat lemah, mengindikasikan dominasi kuat dari variabel luar lain seperti perbandingan sosial, harga diri, dan paparan media visual secara menyeluruh.