* "The Scarlet Letter" by Nathaniel Hawthorne: This book is named after the scarlet letter "A" that Hester Prynn is forced to wear as punishment for adultery.
* "Jane Eyre" by Charlotte Brontë: While this is a very famous novel, the title is not actually named after the protagonist Jane Eyre. It is technically named after the estate of Jane Eyre's childhood home.
There are other books that could be considered, but these are the two that most closely fit the criteria.