: To Determine whether possible sleep bruxism (PSB) is associated with daytime oral habits and sleep behavior in schoolchildren. : A cross-sectional study was conducted with a representative sample of 8-to-10-year-old children (n = 544). The Sleep Behavior Questionnaire (SBQ) was administered to evaluate sleep behavior. Daytime oral habits were evaluated using the Nordic Orofacial Test-Screening. : The prevalence of PSB was 21% and was significantly higher in children with reports of awake bruxism ( < .001; PR = 2.76; 95% CI: 2.01-3.79), snoring ( < .001; PR = 1.93; 95% CI: 1.41-2.65), and sucking/biting the lips daily ( = .034; PR = 1.73; 95% CI: 1.08-2.78). No socioeconomic characteristics were associated with PSB in the final model. : Possible sleep bruxism in schoolchildren is associated with possible awake bruxism, snoring, sleep fragmentation, and daytime sleepiness.