  The structure of the nucleus 25F was investigated through in-beam
{\gamma}-ray spectroscopy of the fragmentation of 26Ne and 27,28Na ion beams.
Based on the particle-{\gamma} and particle-{\gamma}{\gamma} coincidence data,
a level scheme was constructed and compared with shell model and
coupled-cluster calculations. Some of the observed states were interpreted as
quasi single-particle states built on top of the closed-shell nucleus 24O,
while the others were described as states arising from coupling of a single
proton to the 2+ core excitation of 24O.
