Ernest Hemingway won One Pulitzer Prize, receiving the 1953 Pulitzer Prize for Fiction for The Old Man and the Sea.
The award recognized Hemingway’s spare, powerful novella about Santiago, an aging Cuban fisherman engaged in an exhausting struggle with a giant marlin. The book’s success also helped restore his literary reputation after several years without a major new novel.
Hemingway later received the Nobel Prize in Literature in 1954, which is a common source of confusion in this question. The Nobel was a separate international honor, not a second Pulitzer. His Pulitzer was awarded specifically for fiction, while the Nobel citation recognized his broader contribution to literature and his influence on modern prose.