Studies have shown linkages between water, sanitation and hygiene (WASH) and stunting in children under 2 years in sub-Saharan Africa. WASH interventions have shown to reduce stunting rates; however, the biological mechanisms and socio-economic influences responsible for this trend remain poorly understood. This paper reviews the literature regarding these links, and the efficacy of both general WASH interventions and those targeted at children in their first 1,000 days, known as babyWASH, for stunting reduction. Fifty-nine papers published between 2008 and 2019 were reviewed, retrieved from Science Direct, Scopus and Web of Science databases, comprising field trials and data analysis, and literature and systematic reviews. Key findings showed that stunting is directly attributed to diarrhoea, environmental enteric dysfunction and undernutrition although a more comprehensive understanding of these biological mechanisms is necessary. Interventions to interrupt the faecal transmission cycle proved to effectively reduce stunting rates, particularly improved sanitation facilities to reduce open defaecation, increased proximity to water and widespread behavioural change. Methodologies should move away from randomised controlled trials towards selected contexts, mixed data collection methods and inclusion of broader social, cultural and environmental conditions. Improved cross-sectoral collaboration is encouraged, particularly to ensure the complexity of social and contextual factors is fully considered.