John Ogilvie (17 Apr 1797 - 21 Nov 1867)
Georges Ohnet (03 Apr 1848 - 05 May 1918)
Margaret Oliphant (04 Apr 1828 - 20 Jun 1897)
Charles O'Mahony (1884 - 09 Nov 1944)
Nora Tynan O'Mahony (15 Feb 1866 - 13 Dec 1954)
Oliver Onions (13 Nov 1873 - 09 Apr 1961)
Édouard Ordinaire (27 Mar 1812 - 12 Mar 1887)
Oris (see Jean Ingelow)
Ouida (Maria Louise Ramé; 01 Jan 1839 - 25 Jan 1908)
Robert Owen (14 May 1771 - 17 Nov 1858)
John Oxenford (12 Aug 1812 - 21 Feb 1877)