We theoretically investigate the two-photon entanglement in fiber-coupled, two-way cascaded atom–cavity systems. In particular, we demonstrate that, it is possible to generate two-photon entanglement in both weak coupling (atom–cavity coupling rate |g| smaller than the cavity leakage rate κ) and strong coupling regimes (κ<|g|) in this system, when both atoms start off in an excited state. By employing the quantum trajectory method, we characterize the two-photon entanglement in terms of von-Neumann entropy and show that the amount of entanglement exceed considerably (almost double) when κ>|g|. We also quantified the amount of entanglement when instead of two excitations there is a single excitation in the system in the beginning.