Infant colic is a common functional gastrointestinal disorder that affects infants during their first months of life. The etiology of this condition remains unclear. However, some studies suggest lactase deficiency may be a contributing factor. Currently, the evidence on dietary treatment and lactase supplementation for management of infant colic is limited. We aim to systematically review evidence on the efficacy and safety of using a lactase supplementation for managing infant colic. The Cochrane Central Register of Controlled Trials (CENTRAL, the Cochrane Library), MEDLINE, and EMBASE will be searched to identify randomized controlled trials comparing oral lactase supplementation with placebo or no intervention in infants aged less than 6-month-old with infant colic using any recognized definition. The risk of bias will be assessed using the second version of the Cochrane Collaboration's risk-of-bias tool. The main outcome will be the number of responders in each group after treatment, defined as infants who experienced a decrease in daily crying as reported by the study authors. Additional outcomes will include the duration and frequency of crying episodes, infant sleep duration, parental satisfaction, discomfort of infants, number of hospital admissions, family quality of life, and adverse events during the intervention. The study findings will be published in a peer-reviewed journal and will be submitted to relevant conferences.