Abstract: We examine whether stellar flyby simulations can initiate FU Orionis outbursts using 3d hydrodynamics simulations coupled to live Monte Carlo radiative transfer. We find that a flyby where the secondary penetrates the circumprimary disc triggers a 1–2 year rise in the mass accretion rate to 10^−4 M_sun/yr that remains high (&10^−5 M_sun/yr) for more than a hundred years, similar to the outburst observed in FU Ori. Importantly, we find that the less massive star becomes the dominant accretor, as observed.