The direct deposition of diamond coatings on zirconia substrates is hindered by a significant mismatch in thermal expansion coefficients (CTE). This study applied laser surface texturing to create microgrid structures on zirconia to relieve interfacial stress and enhance coating adhesion. Microcrystalline diamond (MCD) coatings were deposited by hot-filament chemical vapor deposition (HFCVD) on textured substrates with varying grid sizes. Through performance comparison, the optimal grid size of 0.2 mm was identified and used to fabricate microcrystalline, nanocrystalline (NCD), and ultrananocrystalline (UNCD) diamond coatings. The coatings were characterized and their tribological properties evaluated. Results show that textured zirconia with a 0.2 mm grid enabled crack-free, well-adhered diamond coatings. The microcrystalline diamond coating exhibited the highest wear resistance with a wear rate of 1.44 × 10 −6 mm 3/N·m but a higher friction coefficient of 0.24. In contrast, the ultrananocrystalline diamond coating showed the lowest friction coefficient of 0.19 with a wear rate of 2.35 × 10 −6 mm 3/N·m. This study provides a viable strategy for designing diamond-coated zirconia components for marine wear applications.