Soil density plays an important role in regulating the migration of greenhouse gases from terrestrial soils to the atmosphere. Soil moisture is one of the main soil physical control determining the fate and transport of gases in soils. This study investigated the transport of methane (CH4) originating from a simulated CH4 source within a variably compacted pasture soil. Simulations were carried out for dry and variably saturated soils. Steady-state methane flow was simulated as a density-dependant, multiphase flow considering a multicomponent mixture of CH4, water vapour and air, under different soil moisture conditions. We used measured soil-water characteristic (SWC) and gas diffusivity data at five density levels (1.1, 1.2, 1.3, 1.4, and 1.5 Mg m-3) to parameterize predictive models. Permeability was estimated using an existing SWC-based saturated hydraulic conductivity function. Results show a distinct effect of soil density on CH4 concentration profiles within the soil. Clear effects of soil moisture on CH4 transport could also be seen in differentially compacted soils. Relatively smaller CH4 concentrations were observed in dry soils where permeability, gas diffusivity and air-filled porosity were higher. With increasing density, the profile-accumulated concentrations > 0.3% increased up to 200 times under the dry condition. In moist soils, on the other hand, smaller air-filled porosity and higher moisture-controlled tortuosity resulted in reduced permeability and gas diffusivity, yielding high CH4 concentrations in the soil profile with only a maximum five-fold increase in the accumulated concentration with increasing density.