Dramatic irony is employed throughout the poem, drawing attention to the empty way of honoring of this "Unknown Citizen." In general, dramatic irony is created when the reader or audience knows more than one or more of the characters. In poetry, then, we might think of the people depicted or discussed as characters; even the speaker could be thought of as a character.

The speaker believes that the questions, "Was he free? Was he happy?" are absurd and have no real bearing or relevance on this citizen's story. Typically, we think of freedom and happiness as pretty important, but the speaker seems to think of meeting one's obligations to society as paramount: so the irony begins. The speaker reports that the man was "fully insured," and when he was once admitted to the hospital, the man left "cured." He had the "right number" of children for a person of his era, and he owned all of the appropriate appliances: kitchen and otherwise. The citizen, it seems, did everything that society says that one is supposed to do: he didn't rock the boat or make waves; instead, he did what seemed right and proper to others at each stage of his life, including his death.

In everything he did, the speaker says, "he served the Greater Community." But is this really what makes a person a "saint," even in "the modern sense"? The speaker does not seem to have any awareness of how ludicrous, how meaningless his praise is. Paying one's Union dues and never getting fired hardly, or should hardly qualify one for sainthood! The speaker, however, does not realize the problem, that his assessment of another person's life is so radically shallow and incomplete, and this is what creates the dramatic irony: we become increasingly aware of this shallowness while the speaker remains ignorant of it.

There are three main types of irony. In verbal irony, a statement means the opposite of its literal meaning. In situational irony, a situation is the opposite of what it is presented to be. In dramatic irony, audiences or readers know something that the characters in a literary work do not.

Though Auden employs a good deal of verbal irony and some dramatic irony, the main thrust of the poem is to express situational irony. The irony is that although the unknown citizen is being celebrated with a "marble monument" for his exemplary life, the poem, in reality, depicts a mindless person brainwashed to conform to the desires of the state. He is more a machine than a human. This is emphasized in the rhetorical questions asked and then dismissed as "absurd" at the end of the poem:

Was he free? Was he happy?

The poem shows that simply doing what you are programmed to do robs a person of freedom and happiness. It is ironic to honor this way of living.

It is also ironic that the state builds a monument to the "unknown" citizen, who is identified not by a name but by an ID tag number, just as an unknown soldier would be. However, monuments are traditionally built to unknown soldiers because they have been so disfigured by battle that their bodies can no longer be identified, or their identity has been lost in some other way. Here, the state has no reason not to "know" its citizens: its building of such a monument ironically shows its complete indifference to the very people it says it wants to honor.

There is verbal irony in the poem "The Unknown Citizen." It is a comparison between a regular citizen, who goes about his business daily and leads a very quiet life, and the Unknown Soldier, who received various monuments from the Allied Powers of WWI.

One piece of irony is that the "unknown citizen" is quite well-known. The reader knows that the citizen worked at the Fudge Motor Company, that he had five children, and that he was married. He was a union member. Everything that is "known" about the man comes from the reports of various experts. The man is known by the paper trail that he left behind in his life. The questions "Was he free?" and "Was he happy?" are only mentioned at the end of the poem as afterthoughts, since according to society, they did not really matter as much as the measurable things he did with his life, such as work in a factory and have children.

Auden's Unknown Citizen received a monument because of his anonymous nature—just a simple man doing regular life things. The Unknown Soldier, on the other hand, received greater plaudits for his heroism, and yet one knows nothing about his life or background.

With a satiric tone, Auden employs verbal irony in his poem. The title itself is ironic:  Alluding to the Unknown Soldier--any of those soldiers killed in World War I who were unidentifiable--that have been honored by a monument to them for their valor in battle,  JS/07/M/378 is ironically compared.  But, he does have an identification number and was alive within his country where people should have known who he is. And even though he is "unknown," and has done nothing to draw attention to himself, he is, ironically, the most respected.

Also ironically, the Unknown Citizen is a hero because he has done nothing out of the ordinary:  He has gone to war when drafted; he has worked at an automobile manufacturer and belonged to the union; he has bought the daily paper; he purchased things on the Installment Plan; he has held politically acceptable opinions and has never contested educational policies.

With another contrast to what is expected, the rhyme is unbalanced in Auden's poem, producing the hint of something wrong. Certainly, the last two lines make use of Auden's verbal irony that prevails throughout his poem:

Was he free?  Was he happy?  The question is absurd:
Had anything been wrong, we should certainly have heard.  

Clearly, Auden satirizes the expectation of conformity in modern life and social organization.  The lackluster life of the citizen, whose name is dispensed with and replaced with a mere number is ironically honored with cold marble; moreover, the man with no name is termed "a saint" for relinquishing his individuality and identity.