<p>Comparative microstructure and mechanical properties of 316L stainless steel reinforced with 1 wt.% ceramic particulates (TiC, WC, SiC, Y₂O₃) fabricated via laser powder bed fusion were investigated. All composite systems exhibit characteristic interleaved molten pool morphologies with reinforcement-induced grain refinement effects: TiC/316L develops ultrafine cellular structures, while WC/316L and Y₂O₃/316L exhibit refined honeycomb-like microstructures. SiC and Y₂O₃ particulates compromise powder sphericity and flowability, and Fe-based interfacial reactions during processing induce crack and pore formation. Texture analysis reveals ceramic-dependent crystallographic behaviors—TiC/316L shows enhanced orientation randomness, SiC/316L intensifies &lt;111&gt; texture components, WC/316L exhibits dominant &lt;001&gt; fiber texture, and Y₂O₃/316L retains a matrix-comparable texture distribution. Grain refinement efficacy varies, with TiC/316L achieving the most pronounced suppression of epitaxial growth through accelerated cooling rates, heterogeneous nucleation site proliferation, and grain boundary pinning. TiC additions also reduce low-angle grain boundaries while increasing Σ3 twin boundaries. Mechanical testing confirms hardness enhancement in all reinforced systems, with TiC/316L exhibiting the highest strengthening efficiency. Tensile testing of TiC/316L demonstrates simultaneous improvements in ultimate tensile strength and yield strength relative to unreinforced 316L, while retaining appreciable ductility and underscoring the tunable reinforcement potential of ceramic particulates in additively manufactured stainless steels.</p>