Ulysses takes us on the journey of two men, Leopold Bloom and Stephen Dedalus, through an hour-by-hour account of their lives for one day. These men cross paths in a series of coincidental events and listeners learn how interconnected they are even though they are not friends.

Dedalus, a teacher, is dissatisfied with life. He spends the morning avoiding mocking friends, listening to a mundane lecture from his superior on life, and walking alone while reflecting on his younger self. Bloom, at the same time, is discovering his wife's affair (although he is having one of his own under a pseudonym), and pursuing an unsuccessful attempt at getting an advertisement ran for a client. Bloom feels like an outsider amongst acquaintances and reminisces on a time when things between he and his wife were good and happy.

Dedalus and Bloom continue to be in the same place at the same time throughout the novel as the story continues into themes of xenophobia, the quest for paternity, heroism in compassion, and many other of life's questions. Ulysses was written to mimic The Odyssey by Homer in a modern day retelling of the poem and has many parallels between the characters and plot events making the novel an epic adventure through two very ordinary lives.