We study the diffusion of self-interstitial atoms {(SIAs)} and {SIA} clusters in vanadium via molecular dynamics simulations with an improved {Finnis–Sinclair} potential (fit to first-principles results for {SIA} structure and energetics). The present results demonstrate that single {SIAs} exist in a 〈1&\#xa0;1&\#xa0;1〉-dumbbell configuration and migrate easily along 〈1&\#xa0;1&\#xa0;1〉 directions. Changes of direction through rotations into other 〈1&\#xa0;1&\#xa0;1〉 directions are infrequent at low temperatures, but become prominent at higher temperatures, thereby changing the migration path from predominantly one-dimensional to almost isotropically three-dimensional. {SIA} clusters (i.e., clusters of 〈1&\#xa0;1&\#xa0;1〉-dumbbells) can be described as perfect prismatic dislocation loops with Burgers vector and habit planes of 1/2〈1&\#xa0;1&\#xa0;1〉{2&\#xa0;2&\#xa0;0} that migrate only along their glide cylinder. {SIA} clusters also migrate along 〈1&\#xa0;1&\#xa0;1〉-directions, but do not rotate. Both single {SIAs} and their clusters exhibit a highly {non-Arrhenius} diffusivity, which originates from a combination of a temperature dependent correlation factor and the presence of very low migration barriers. At low temperature, the diffusion is approximately Arrhenius, while above room temperature, the diffusivity is a linear function of temperature. A simple model is proposed to describe these diffusion regimes and the transition between them.