This study developed a solid self-nanoemulsifying drug delivery system (S-SNEDDS) to improve the oral bioavailability of poorly soluble carvedilol using mesoporous silica nanoparticles (MSNs). The liquid self-nanoemulsifying drug delivery system (L-SNEDDS) consisted of carvedilol, Peceol, Tween 80, and Labrasol in a weight ratio of 10:25:50:25. The liquid SNEDDS was suspended in MSN at various ratios and spray-dried to produce S-SNEDDS. The emulsion size, PDI, solubility, and dissolution of various ratios of MSN were evaluated to make the optimal S-SNEDDS. The optimal S-SNEDDS, manufactured using a ratio of MSN to L-SNEDDS 1000 at 500, formed a nanoemulsion and achieved efficient supersaturation compared to carvedilol alone, which significantly improved drug solubility (approximately 400 times), dissolution (approximately 5.7 times at 60 min), area under the curve (AUC) (21.7 times), and maximum plasma concentration (Cmax) (15.7 times). In addition, the physicochemical properties of the optimal S-SNEDDS were evaluated by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR), particle size, and scanning electron microscopy (SEM) images. S-SNEDDS showed a smaller particle size than MSN alone, and the crystalline drug was transformed into an amorphous substance, resulting in encapsulation in MSN. These results suggest that MSN can be a novel biocompatible carrier contributing to a safer and more effective delivery system.