Books about Conduct of life -- Juvenile fiction (sorted alphabetically)
- Olive Leaves; Or, Sketches of Character L. H. Sigourney
- On Angels' Wings Mrs. Greene
- On Board the Esmeralda John C. Hutcheson
- Once upon a time animal stories Carolyn Sherwin Bailey
- On Guard: Mark Mallory's Celebration Upton Sinclair
- Only an Irish Boy; Or, Andy Burke's Fortunes Jr. Horatio Alger
- On the Irrawaddy: A Story of the First Burmese War G. A. Henty
- On Time; or, Bound to Get There Oliver Optic
- Opportunities Susan Warner
- Oriel Window Mrs. Molesworth
- Orphan's Home Mittens, and George's Account of the Battle of Roanoke Island Aunt Fanny
- Oscar in Africa Harry Castlemon
- Oscar; Or, The Boy Who Had His Own Way Walter Aimwell
- Our Den E. M. Waterworth
- Our Fellows; Or, Skirmishes with the Swamp Dragoons Harry Castlemon
- Our Little Lady Emily Sarah Holt
- Out in the Forty-Five Emily Sarah Holt
- Out with Garibaldi: A story of the liberation of Italy G. A. Henty
- Owen's Fortune; Or, "Durable Riches" Mrs. Frederic West
- Oxbow Wizard Theodore Goodridge Roberts
- Pair of Clogs Amy Walton
- Palace in the Garden Mrs. Molesworth
- Parent's Assistant; Or, Stories for Children Maria Edgeworth
- Patience Wins: War in the Works George Manville Fenn
- Patty and Azalea Carolyn Wells