  We consider semi-direct gauge mediation models of supersymmetry breaking
where the messengers are composite fields and their supersymmetric mass is
naturally generated through quartic superpotential couplings. We show that such
composite messenger models can be easily embedded in quiver gauge theories
arising from D-branes at Calabi-Yau singularities, and argue that semi-direct
gauge mediation is in fact a very natural option for supersymmetry breaking in
D-brane models. We provide several explicit examples and discuss their salient
phenomenological properties.
