Steinbeck scholar John Timmerman sums up the book's influence: "The Grapes of Wrath may well be the most thoroughly discussed novel – in criticism, reviews, and college classrooms – of 20th century American literature." The Grapes of Wrath is referred to as a Great American Novel.
At the time of publication, Steinbeck's novel "was a phenomenon on the scale of a national event. It was publicly banned and burned by citizens, it was debated on national radio; but above all, it was read." According to The New York Times, it was the best-selling book of 1939 and 430,000 copies had been printed by February 1940. In that month it won the National Book Award, favorite fiction book of 1939, voted by members of the American Booksellers Association. Soon it won the Pulitzer Prize for Fiction.
The book was noted for Steinbeck's passionate depiction of the plight of the poor, and many of his contemporaries attacked his social and political views. Bryan Cordyack writes, "Steinbeck was attacked as a propagandist and a socialist from both the left and the right of the political spectrum. The most fervent of these attacks came from the Associated Farmers of California; they were displeased with the book's depiction of California farmers' attitudes and conduct toward the migrants. They denounced the book as a 'pack of lies' and labeled it 'communist propaganda'". Some claimed that his novel was filled with inaccuracies  , and others accused Steinbeck of exaggerating camp conditions to make a political point. Steinbeck had visited the camps well before publication of the novel and argued their inhumane nature destroyed the settlers' spirit.
In 1962, the Nobel Prize committee cited Grapes of Wrath as a "great work" and as one of the committee's main reasons for granting Steinbeck the Nobel Prize for Literature.
In 2005 Time magazine included the novel in its "TIME 100 Best English-language Novels from 1923 to 2005". In 2009, The Daily Telegraph of the United Kingdom included the novel in its "100 novels everyone should read". In 1998, the Modern Library ranked The Grapes of Wrath tenth on its list of the 100 best English-language novels of the 20th century. In 1999, French newspaper Le Monde of Paris ranked The Grapes of Wrath as seventh on its list of the 100 best books of the 20th century. In the UK, it was listed at number 29 among the "nation's best loved novels" on the BBC's 2003 survey The Big Read.