We provide a comprehensive analysis of the acceleration of magnetic monopoles in intergalactic magnetic fields. We demonstrate that monopoles with intermediate to low masses can be accelerated to relativistic velocities. This can significantly affect direct and indirect searches for magnetic monopoles. As an example, we show that the Parker bound is relaxed in the presence of intergalactic fields. We also find that a cosmic population of monopoles can produce significant backreaction on the intergalactic fields.
