The very title of the book is ironic. Throughout the story, Oskar is forced to deal with the terrible trauma caused by his father's death, a trauma that is "extremely loud and incredibly close." Yet the one person who can help him deal with his loss—his grandfather—doesn't speak and so Oskar is left to fend for himself emotionally.

A further irony comes in the fact that the death of Oskar's father has separated the young boy from his family while at the same time bringing the rest of his family closer together. It is ironic indeed that it is only in the tragic aftermath of Thomas's death that Oskar's estranged grandparents are finally brought back together after a lengthy period of separation.

There is plenty of irony in this incredible novel. Let us remember that irony reflects a gap between reality and the way that it is presented. There is a sense in which the character of Oskar, the strange and quirky twelve-year-old narrator who tells us his story, and the way that he is presented to us features dramatic irony, as he is unable to recognise how some of his behaviour is so unsuitable in the social situations that he finds himself in. This would be an example of dramatic irony, as we as the readers and the other characters in this novel recognise that what he is saying is unsuitable or doesn't "fit" the social situation whereas Oskar is not able to work this out for himself. 

A classic example comes when he meets the first of his list of Blacks, and asks to kiss her:

"Excuse me?" she said, although, on the other hand, she didn't pull her head back. "It's just that I like you, and I think I can tell that you like me." 

Oskar is unable to understand why her age of 48 and her married status would make it impossible for them to kiss, and his naivety, or different way of looking at the world is something that the novel explores again and again as we come to realise that Oskar is a child who has an incredibly unique viewpoint.