The aim of this study was to produce capsule-shaped floating devices (CFD) using a fused deposition modeling (FDM) three-dimensional (3D) printer, for controlling the release and gastric retention of domperidone (DOM) tablets (Motilium-MⓇ). In order to enhance the buoyancy of the devices, a hollow cap with different wall thicknesses (1.2–1.5 mm) was printed with a hydrophilic (polyvinyl alcohol, PVA) filament. The body of the device was made from a hydrophobic (polylactic acid, PLA) filament. Bodies with aperture sizes (1–2 mm) were produced to investigate how this would affect drug release. Morphology, weight variation, ex vivo and in vivo floating time and drug release characteristics were examined. The results revealed that increasing the cap thickness of the devices (1.2 to 1.3 mm) increased the total floating time (TFT). The maximum TFT (10 h) with floating lag time (FLT) < 5 s was observed from Motilium-MⓇ incorporated CFD3–5 (cap with 1.3-mm wall thickness). Decreasing the size of the holes on the devices led to the sustained release of DOM. The CFD5 (cap with 1.3-mm cap thickness and 1.5-mm hole width) delivered approximately 98% release in 10 h, and the release kinetics fit well with the zero-order kinetics (R2 > 0.95). In vivo floating studies in rabbits showed that the floating time of CFD5 was more than 10 h. These results demonstrated that the CFD was successfully designed to provide gastro-retentive drug delivery with the capacity to float and provide sustained drug release.