A New Jersey pediatrician and poet who occasionally works for barter during the Great Depression. He serves as the speaker of the poem, an impulsive husband who gives in to the sensory temptation of eating chilled plums meant for someone else. He grounds his daily life in science and medicine while maintaining an appreciative eye for the everyday magic of ordinary objects.

The spouse of the speaker who prepares the household's meals and saves plums in the icebox for her morning breakfast. She acts as the unseen audience for the poem's half-hearted apology. She eventually writes her own practical, wryly affectionate response poem detailing the other food she has prepared for him.

A struggling poet and student of languages who becomes a maverick philosopher within the Modernist movement. He encourages young writers to strip away ornate traditions in favor of direct, minimal images. His strict artistic dictates eventually cause ideological friction with Williams's more conversational approach.