This paper studies the impact of different infill patterns on 3D printed dielectric resonator antennas (DRAs). Different infill patterns with the same infill percentage setting can have very different actual material infill percentages, which can result in a variation in the effective relative permittivity. This consequently affects the impedance matching and resonance frequency of the 3D printed dielectric antennas. Furthermore, the orientation of the 3D printed DRA needs to be taken into account, due to the anisotropic structure within the printed material. Based on experimental results, rectilinear and grid patterns are generally preferred for 3D printed antenna designs, considering their robustness and printing accuracy.