A configuration-interaction calculation of the electronic energies of the OH radical has been performed, using from 34 to 46 configurations for the doublet states; and from 11 to 25 configurations for the quartet states. The results are presented for the six lowest states of 2Σ+, 2Σ−, 2Π, 2Δ; 4Σ+, 4Σ−, 4Π, and 4Δ symmetries. The calculations have been performed for a range of internuclear distances from 0.8 to 3 Å. The method of computation has been designed to give the kind of accuracy for the lowest three or four states of each symmetry which could be useful in the empirical analysis of the hitherto unanalyzed spectrum of OH in the 1850 Å region.