Background: Health-related behaviours and attitudes acquired in childhood significantly shape health behaviours in adulthood and play an important role in preventing children from becoming overweight. Interventions incorporating parental involvement can provide outstanding support in shaping a child’s health-related behaviour. However, parental involvement has not been investigated from the perspective of efficacy except for obesity. Therefore, this systematic review investigates school-based physical activity intervention programmes incorporating parental involvement. We aim to explore the impact of these programmes and the parental involvement they provide on behaviours that influence child health, which are essential for preventing children and adults from becoming overweight and promoting health-conscious lifestyles. Methods: This systematic literature review follows PRISMA guidelines. The EBSCO Discovery Service Search Engine was used for searching for literature. Papers included met the following inclusion criteria: (1) reported original, empirical research or systematic review published in a peer-reviewed journal; (2) primary or secondary school age (6–18 years) as the target population; (3) examined school-based sport or health prevention and intervention programs; (4) only healthy children and youth in the indicated age group; (5) school-based prevention or intervention program; (6) examines parental involvement; (7) in the English language, and (8) in disciplines of education, psychology, social work, sociology, social sciences and humanities. Results: An extremely limited number of interventions of sufficient quality address the role of parental involvement (N = 17). The forms of parental involvement show a huge variety, ranging from leaflets, home packs, sports organisations “forced” by the pandemic, parent meetings, programmes, courses, and school programmes with diverse children over several months (cooking together, gardening, playing sports together, etc.). Therefore, it is difficult to measure their effectiveness and impact. Conclusions: The impact of parental involvement on children’s health behaviour, especially physical activity and nutrition, as two of the most important factors in preventing them from becoming overweight, are unclear, and other correlations, e.g., academic achievement, are scarce.