Rotational spectra have been assigned for five isotopic species of the OC...HBr hydrogen-bonded molecular complex by using pulsed microwave Fourier transform spectroscopy in a Fabry-Perot cavity and a pulsed supersonic nozzle as the molecular source. The rotational constants, centrifugal distortion constants, Br nuclear-quadrupole-coupling constants, and Br spin-rotation constants were determined and from them, the vibrationally averaged structure of OCHBr was derived. This structure is consistent with a linear geometry at equilibrium and an atomic arrangement as written above. The intermolecular potential binding CO to HBr is discussed.