Tuvalu, like many Pacific Island nations, is facing a severe obesity epidemic, which is strongly associated with obstructive sleep apnoea (OSA) - a condition linked to multiple health complications and a growing public health burden. Lifestyle interventions such as home gardening have emerged as potential strategies to address obesity and its related conditions. We investigated the association between home gardening and OSA risk in Tuvalu and explored how behavioural and demographic factors may modify this relationship. We conducted a nationwide cross-sectional study in Tuvalu in 2023 using the COMmunity-based Behaviour and Attitude Study in Tuvalu (COMBAT) questionnaire. We assessed OSA risk using the validated eight-item 'Snoring, Tiredness, Observed apnoea, high blood Pressure, Body mass index, Age, Neck circumference, and Gender' (STOP-Bang) questionnaire, and home gardening status was self-reported. We used logistic regression models, including multivariable adjustments and overlap weighting, to assess the association between home gardening and OSA outcomes, including total STOP-Bang score, OSA risk (≥3 points), and related symptoms (snoring, daytime fatigue, witnessed apnoea). We conducted stratified analyses by behavioural and demographic characteristics. We included 849 adult participants (mean (x̄) age = 32.9 years; 51.9% female). Among individuals who exercised, home gardening was associated with lower STOP-Bang scores (x̄ difference = -0.30; 95% confidence interval (CI) = -0.59, -0.01, P = 0.040 in overlap weighting model) and with lower odds of STOP-Bang score ≥3 (adjusted odds ratio = 0.85; 95% CI = 0.73, 0.98, P = 0.026) than non-gardeners. Furthermore, home gardening was associated with significantly lower odds of snoring among individuals who smoked, consumed alcohol, or exercised, and with borderline lower odds of STOP-Bang score ≥3 among individuals who consumed alcohol. In the COMBAT study, home gardening was associated with lower OSA probability among subgroups with specific lifestyle factors. These findings suggest that home gardening could serve as a feasible and community-based intervention to mitigate OSA risk in Tuvalu and similar low-resource settings.