As an additive manufacturing (AM) technology, fused deposition modeling (FDM) is widely used to fabricate highly complex components. Polymer components fabricated by FDM technique have weak mechanical properties. To enhance the mechanical properties, 3D printing of polymer composites is done by reinforcing particles, nanomaterials, short and continuous fibers into thermoplastic polymers. The thermal, flame retardant, and impact properties of a continuous kevlar fiber-reinforced onyx 3D-printed composite are investigated in this study. Additionally, the effect of fiber arrangement and orientation (0 , 90 , 0 /90 , and +45 /À45 ) on the impact strength of 3D-printed composites have been investigated. The impact strength of the 3D-printed composite specimens was determined using izod impact testing. It was found that specimens with fiber arrangement having fiber and matrix layer configuration as 21O| 20K|20O|20K|21O have a higher impact strength and specimens with fiber arrangement as 31O|40K|31O have lower impact strength. Furthermore, specimen 3D printed with a unidirectional 0 fiber angle had the highest impact strength, while specimen 3D printed with a unidirectional 90 fiber angle had the lowest impact strength. Furthermore, flammability tests and thermogravimetric analysis were performed to investigate the flame retardant and thermal properties of 3D-printed composites. Morphological study of onyx and kevlar fiber filament was also done using scanning electron microscope (SEM).