The speaker of the poem serves as a collective voice representing the passengers on a ship. By using the pronoun "We," the speaker establishes a shared experience of viewing the natural world. They value stillness and the internal depths of the imagination, finding deeper meaning in a stationary mass of ice than in the forward momentum of oceanic travel.

Elizabeth is an acclaimed poet who spends much of her early life dealing with physical illness and family instability. Inheriting financial independence from her late father, she uses her resources to travel extensively across Europe, North Africa, and South America. She deliberately resists the formal experimentation and confessional trends of her era, preferring to write in relatively conventional free-verse influenced by Victorian and romantic writers.

A hypothetical figure introduced by the speaker to illustrate a point. The sailor represents practical oceanic concerns but is used to emphasize the iceberg's overwhelming aesthetic and imaginative power, as he would willingly give up his sight just to behold it.

Gertrude is the mother of Elizabeth Bishop. After the death of her husband when Elizabeth is eight months old, she experiences severe mental illness. She is institutionalized when her daughter is five years old, separating the two permanently and contributing to the child's turbulent early life.

Maude is Elizabeth Bishop's maternal aunt. When her niece experiences declining physical and emotional health in Worcester, Maude brings the child into her home. Because poor health prevents regular school attendance, Maude takes charge of her niece's education and introduces her to classic Victorian poetry.

Marianne is a prominent American modernist poet. A college librarian introduces her to Elizabeth Bishop, sparking a lifelong connection. She serves as a primary mentor and one of the greatest influences on Bishop's developing poetic voice until her death in 1972.

Louise is a college acquaintance and travel companion. She and Bishop spend two years journeying across Europe and North Africa, providing the worldly experiences that inspire much of Bishop's first poetry collection.

Lota is Elizabeth Bishop's romantic partner. She builds a life with Bishop in South America, providing the environmental and emotional context for the poet's collection focusing on questions of travel.

Robert is a seminal American confessional poet and one of Elizabeth Bishop's closest friends. He writes long, historical verse that draws heavily on autobiography. His approach to poetry stands in direct contrast to Bishop's outward-looking, observational style.