The demand for highly‐durable protective coatings for use in extreme environments is continually growing, however, poor durability and adhesion restricted their practical applications. Herein, we prepared a novel solution‐processable graphene‐based copolymer for fabricating highly‐durable protective coatings. The random‐structured copolymer GO‐g‐(PMMA‐co‐PMPS) was prepared by graphene‐based initiator (GO‐g‐Cl) initiating methyl methacrylate (MMA) and 3‐methacryloxypropyltrimethoxysilane (MPS) via surface‐initiated atom transfer radical polymerization (SI‐ATRP). The copolymers rendered the coatings with high transmittance (~95%), high hydrophobicity (water contact angles = 113.8 ± 2.13°), and strong adhesion (1.26–1.38 MPa). Tetrahydrofuran (THF)‐casted coating surface presented a higher Si content and greater surface roughness than that cast from dimethyl carbonate (DMC), yielding more hydrophobic coating than those cast from DMC. The coatings could be coated on different substrates (glass, aluminum, and sandstone); and besides, the structures and performance of the coatings remained unchanged, even exposing to acid/alkali, salt, and ultraviolet light irradiation. These high‐performance properties make the GO‐based copolymers ideal candidates for fabricating high‐durability protective coatings.