Sleep bruxism (SB) is a masticatory muscle activity during sleep that can cause several consequences to the stomatognathic system. This systematic review investigated the impact of SB on oral health-related quality of life (OHRQoL) of 0- to 6-year-old children. Literature search was undertaken through PubMed/MEDLINE, LILACS, Scopus, TRIP, Livivo databases, and grey literature. The search was conducted with no publication year or language limits. Two reviewers independently selected the studies, extracted the data and assessed the risk of bias. The quality of evidence was assessed using GRADE. From 185 potentially eligible studies, three were included in the review. All studies were conducted in Brazil, published between 2015 and 2017, and used the B-ECOHIS instrument to evaluate OHRQoL. Two studies found no association between SB and OHRQoL, whereas one showed a significant negative impact of SB on the OHRQoL of children. SB was associated with respiratory problems, presence of tooth wear, dental caries, malocclusion as well as income and pacifier use. Risk of bias ranged from moderate to high, and the quality of evidence was judged as very low. The evidence is currently insufficient for definitive conclusions about the impact of SB on OHRQoL of children.