Bedtime procrastination is defined as the volitional delay of going to bed, without any external circumstances causing the delay, and is associated with inadequate sleep. Alleviating bedtime procrastination is an important target for interventions promoting adequate sleep, yet the correlates of bedtime procrastination are poorly understood. This study examined (1) correlates of bedtime procrastination, and (2) strength and direction of the association between bedtime procrastination and sleep outcomes. Six databases (CINAHL, EMBASE, PsychINFO, PubMed, Scopus, Web of Science) were searched from inception to September 2021 against pre-determined eligibility criteria. Forty-three studies were included (GRADE = low). Meta-analysis revealed that bedtime procrastination had a moderate negative association with self-control (z = −0.39; CI: −0.45, −0.29) and a moderate positive association with evening chronotype (z = 0.43; CI: 0.32, 0.48). Furthermore, bedtime procrastination was moderately negatively associated with sleep duration (z = −0.31; CI: −0.37, −0.24), sleep quality (z = −0.35; CI: −0.42, −0.27) and moderately positively associated with daytime fatigue (z = 0.32; CI: 0.25, 0.38). Further high-quality studies are needed to identify causal relationships between bedtime procrastination and correlates, as well as bedtime procrastination and sleep. Future work will guide the development of interventions targeting bedtime procrastination for improved sleep outcomes. Study registration: PROSPERO registration number CRD42021248891.