O'Connor borrowed her title from a popular blues song written by Eddie Green and recorded by Bessie Smith in 1927. "A Good Man is Hard to Find," as its name suggests, is a song about a woman's love for a man who inevitably betrays her and treats her so "mean" that she wishes he were dead.
The title's irony is evident when the family stops at a barbecue for lunch. Red Sammy, the restaurant owner, and the grandmother, have a platitudinous conversation about how "These days you don't know who to trust." When Sammy mentions two strangers he let "charge" gasoline the previous week, and asks, "Now why did I do that?" the grandmother's immediate response is, "Because you're a good man."
Irony is underscored when Red Sammy mops off his sweating face and yells at his wife-waitress to "get these people's order." Prophetically, Red Sammy declares: "A good man is hard to find." [...] "Everything is getting terrible."
The family's fate unfolds just outside of Tombsboro, when their diversion and accident place them in the Misfit's path. As her family members are led to the woods and shot, the grandmother pleads for her life, telling the serial killer, "you shouldn't call yourself the Misfit because I know you're a good man."
The title of the story is ironic because it represents the point of view of the grandmother. On the one hand, it represents her limited and critical view of the world, where she sees herself as "good" but others deeply faulted. But on the other hand the title also carries truth in that pure goodness, in O'conner's world, does not exist in that we all are deeply flawed. The "good man" that the grandmother finds is a murderer, but he is good because he enables her to understand herself and him, if only briefly, before he kills her.
Flannery O'Conner's works as a whole grapple with religious questions and themes. Therefore, a "good man" is a universal type that may apply to a righteous man or woman. In this particular story, the convict and murderer is actually a sympathetic character and somewhat of a good man because his evil nature appears to be a creation of an unjust society that treated him poorly. Although he may be considered somewhat "good", he is still a murderer who kills the grandmother's family, thus making true good, difficult to find.
In addition, the grandmother in the story is very self-centered and cares little to nothing for others. Her means to find goodness comes in the form of the convict, a quasi-Christ figure, who helps her to realize the errors of her way, thus helping her find redemption in her death after the convict murders her. The story implies true goodness is not only hard to find but is not fully achieved even in death and the afterlife.