AbstractSleep is vital for maintaining overall health and well-being. This study investigated the relationship between sleep hygiene and social rhythm and aimed to identify the key predictors of sleep quality among young Malaysian adults. Conducted at Universiti Pendidikan Sultan Idris in Perak, Malaysia, the research utilized a longitudinal survey design. A total of 113 university students participated, completing either a paper-based or an online survey. The survey comprised a demographic questionnaire, Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), Sleep Hygiene Inventory (SHI), Social Rhythm Metric (SRM II-5), Consensus Sleep Diary (CSD), and Stanford Sleepiness Scale (SSS). Participants also recorded sleep and social rhythm diaries for one week. The results showed that Malaysian young adults generally exhibited good sleep hygiene and an above-average social rhythm, with mean scores of 12.52 (SD = 6.7) for sleep hygiene and 4.78 (SD = 1.62) for social rhythm. Most pa.....