In the title compound, C23H18FNO3, the tricyclic 9-fluorenyl system is approximately planar (r.m.s. deviation = 0.0279 Å). The N-C(=O) bond length is comparatively short [1.359 (3) Å], which is typical for such conjugated systems. The N atom has a planar configuration [sum of bond angles= 359.8°] due to conjugation of its lone pair with the π-system of the carbonyl group. In the crystal, a three-dimensional network is formed through N-H⋯O and O-H⋯O hydrogen bonds between the amide and carb-oxy-lic acid groups and carbonyl O-atom acceptors.