| The Orphans of Glen Elder
Margaret M. Robertson | |
| The Orpheus C. Kerr Papers, Series 1
R. H. Newell | |
| The Orpheus C. Kerr Papers, Series 2
R. H. Newell | |
| The Orpheus C. Kerr Papers, Series 3
R. H. Newell | |
| The O'Ruddy: A Romance
Stephen Crane; Robert Barr | |
| The Osage tribe, two versions of the child-naming rite / (1928 N 43 / 1925-1926 (pages 23-164))
Francis La Flesche | |
| The Osbornes
E. F. Benson | |
| The Other Fellow
Francis Hopkinson Smith | |
| The Other Girls
A. D. T. Whitney | |
| The other half
Edwin L. Sabin |
