We present a determination of the LEP beam energy using "radiative return" fermion-pair events recorded at centre-of-mass energies from 183 GeV to 209 GeV. We find no evidence of a disagreement between the OPAL data and the LEP Energy Working Group's standard calibration. Including the energy-averaged 11 MeV uncertainty in the standard determination, the beam energy we obtain from the OPAL data is higher than that obtained from the LEP calibration by 0 +- 34 (stat.) +- 27 (syst.) MeV.