Abstract: Liberalism is an ideology that emerged in the 18th century and that advocates for striving to secure the rights of freedom of speech and religion. In Malaysia, liberalism is presented as ‘Liberal Islam’ to demonstrate its harmony with Malaysian culture and society. It is propagated through various social media platforms, especially Twitter. Social media has become a favorable platform for propagating the idea of ‘Liberal Islam’, and its function which is widely and easily accessible is an important factor that contributed to the dissemination of controversial ideology. Therefore, this study aims to develop an instrument measuring the perception of Muslims towards Liberal Islam’s interpretation of marital issues. The principal data acquisition involved the utilization of a self-administered questionnaire, disseminated through an online survey to 35 participants during the preliminary investigation. The selection of respondents employed a purposive sampling approach targeting Twitter users. The analysis of the gathered quantitative data was done by utilizing SPSS version 29.0. The instrument was developed based on a literature review, Content Validation Index (CVI), and pilot test. The instrument is divided into three constructs: first, knowledge about liberalism; second, knowledge about ‘Liberal Islam’; and third, perception towards the interpretation of ‘Liberal Islam’ on marital issues. The CVI results showed that the questionnaire is valid. A pilot study was conducted to test the reliability of the items. The Cronbach Alpha (α) values for the first (0.739), second (0.793), and third (0.869) constructs were adequate. Overall, these results indicate that the self-constructed questionnaire has succeeded in developing an instrument that measures the respondent’s knowledge of liberalism and ‘Liberal Islam’ and their perception of ‘Liberal Islam’ interpretation. The outcome of this study is expected to counteract the spread of ‘Liberal Islam’ ideology among the Malaysian youth, thus preserving the authentic interpretation of the Quran and Hadith. Abstrak: Liberalisme ialah satu ideologi yang muncul pada abad ke-18 yang menyokong usaha untuk mendapatkan hak kebebasan dalam bersuara dan beragama. Di Malaysia, liberalisme diperkenalkan sebagai ‘Islam Liberal’. Hal ini kerana, untuk menunjukkan keharmonian dalam budaya masyarakat Malaysia. Ia disebarkan melalui pelbagai platform media sosial terutamanya Twitter kerana fungsinya yang mudah diakses secara meluas oleh belia remaja. Oleh itu, kajian ini bertujuan untuk membangunkan instrumen bagi mengukur persepsi belia di Malaysia terhadap tafsiran Islam Liberal mengenai isu perkahwinan. Pengumpulan data utama melibatkan penggunaan soal selidik yang dibina sendiri, disebarkan melalui dalam talian kepada 35 responden semasa kajian rintis. Pemilihan responden melibatkan penggunaan pendekatan persampelan bertujuan yang menumpukan kepada pengguna Twitter. Analisis data kuantitatif yang diperoleh diuji dengan menggunakan SPSS versi 29.0. Instrumen ini dibangunkan berdasarkan kajian literatur, Indeks Pengesahan Kandungan (CVI), dan ujian rintis. Instrumen ini dibahagikan kepada tiga konstruk; pertama, pengetahuan tentang liberalisme; kedua, pengetahuan tentang ‘Islam Liberal’; dan ketiga, persepsi terhadap tafsiran ‘Islam Liberal’ terhadap isu rumah tangga. Keputusan CVI menunjukkan bahawa soal selidik adalah sah. Kajian rintis telah dijalankan untuk menguji kebolehpercayaan item tersebut. Kajian nilai Cronbach Alpha (α) bagi konstruk pertama (0.739), kedua (0.793), dan ketiga (0.869) adalah memadai. Secara keseluruhannya, keputusan ini menunjukkan bahawa soal selidik yang dibina sendiri telah berjaya membangunkan instrumen yang mengukur pengetahuan responden tentang liberalisme dan ‘Islam Liberal’ dan persepsi terhadap tafsiran ‘Islam Liberal’. Hasil kajian ini diharapkan dapat menangkis penularan fahaman ‘Islam Liberal’ dalam kalangan belia Malaysia, sekali gus memelihara tafsiran terhadap ayat-ayat suci al-Quran dan Hadis.