1. The removal and exclusion of non-native ungulates for conservation of biodiversity is common globally, including on tropical Pacific Islands. However, the poorly quantified effects of ungulate exclusion on fuels and wildfire may represent an important conservation trade-off.2. We measured fuels (live and dead fuel loads, type, height and continuity) and modelled potential wildfire behaviour (flame height and rate of spread) inside and outside of 13 ungulate exclosures, three of which received active ecological restoration (e.g. planting of native shrubs and trees), across a 2,740 mm mean annual rainfall (MAR) gradient on the Island of Hawaii. Differences in fuel characteristics and modelled wildfire behaviour inside versus outside of ungulate exclosures were assessed using linear mixed effects analyses.3. Non-native ungulate removal, in general, increased fine fuel loading (average change ranged from −0.7 to 11.3 Mg/ha), shrub fuel loading (−0.1 to 5.6 Mg/ha) and modelled flame lengths (−0.2 to 1.9 m). Post-removal fine fuel loading and