BACKGROUND: Adequate access to water, sanitation and hygiene (WASH) is imperative for health and wellbeing, yet people with disabilities, people with incontinence and people who menstruate often experience unmet WASH requirements. METHODS: In 2019 we completed a mixed-methods study in two provinces of Vanuatu, (SANMA and TORBA). The study comprised 1) a population-based disability survey using the Washington Group Short-Set 2) a nested case-control study to explore associations between WASH, disability and gender, and 3) an in-depth qualitative assessment of the experiences of WASH users with additional requirements: people with and without disabilities who menstruate, or experience incontinence. FINDING: 11,446 households (response rate 85%) were enrolled into the survey. All-age disability prevalence across the two provinces was 2.6% (95% Confidence Interval 2.5-2.8), increasing with age. 814 people with, and 702 people without disabilities participated in the case-control study. People with disabilities were statistically more likely to experience barriers in seven of eight intra-household indicators. WASH-related stigma, reliance on informal caregivers, and under-resourcing of WASH personnel were critical issues for people who menstruate or experience incontinence. INTERPRETATION: People with disabilities, people with incontinence and people who menstruate in Northern Vanuatu face continued challenges in accessing safe, affordable and appropriate WASH that meets their requirements. Outputs from this study have supported progression towards gender and disability-inclusive WASH programming in the area and highlighted the value of mixed-methods research. FUNDING: The research was funded by the Australian Government's Water for Women fund and donations from the Australian public.