In article number 1805228, Ihsan Amin, Tao Zhang, Rainer Jordan, and co‐workers present the direct covalent functionalization of hexagonal boron nitride (hBN) with polymer brushes under mild conditions. Photopolymerization results demonstrate the formation of thick and homogeneous (micropatterned, graded) polymer brushes covalently bound to hBN. The brush layer mechanically and chemically stabilizes the material and allows facile handling as well as long‐term use in water splitting hydrogen evolution reactions.