In the mol-ecular structure of the title compound, C(20)H(15)NO(2), the isoindolin-1-one unit is planar, the maximum atomic deviation being 0.048 (2) Å. The two biphenyl rings are twisted with respect to the isoindolin-1-one plane, making dihedral angles of 33.21 (9) and 33.34 (9)°. The two benzene rings of the biphenyl substituent are oriented at a dihedral angle of 35.43 (11)° to each other. An intra-molecular O-H⋯O inter-action occurs and inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure.