The oral bioavailability of many medications, especially BCS Class II and Class IV substances, is significantly limited by poor water solubility. Three main options for improving bioavailability are examined in this review: solid dispersions, lipid-based drug delivery systems, and nanotechnology-based methods. Lipid-based systems like SEDDS, SMEDDS, and SNEDDS promote solubilisation and absorption, whereas solid dispersions improve drug dissolution by amorphization and improved wettability. By increasing surface area and improving permeability, nanotechnology-based carriers—such as nanoparticles, nanosuspensions, and nanoemulsions—further boost drug delivery. These technologies considerably increase oral bioavailability, solubility, and dissolution rate, according to the reviewed research. Stability, scalability, production, and regulatory approval are still issues, though. Promising prospects for future developments in oral medication delivery are provided by cutting-edge techniques, including hybrid delivery systems and formulation design aided by artificial intelligence.