Ignatius J. Reilly is not just the protagonist of A Confederacy of Dunces; he has also passed into the common cultural lexicon and become a beloved figure in literature. As an overweight, slovenly, prideful, lazy, but highly educated man, he is arrogant to the extreme and easily wounded by even the smallest collision or slightest insult. He possesses a huge ego and a fragile sense of self-worth. He lives at home with his elderly mother at the beginning of the novel, and the story shows how his situation slowly deteriorates until he is forced to confront his deepest beliefs and find a new way to exist in an ever-changing America.

Ignatius is introduced to the audience at the age of 30. At this point in his life, he exists on the fringes of society and contributes little to humanity. Seemingly helpless and terrified of real work, he spends his days watching television, arguing, and judging those around him. A ridiculous character himself, Ignatius finds regular people wanting. They fail to measure up to the high (and practically medieval) standards he sets for those around him, standards he does not meet himself. He is a deluded hypocrite, yet he is the main protagonist.