He was of German American and Irish American descent.
Steinbeck, John Ernst was born on February 27, 1902 in Salinas, California, United States. Son of John Ernst and Olive (Hamilton) Steinbeck.
His father, John Steinbeck, Sr., served as the Monterey County Treasurer while his mother, Olive (Hamilton) Steinbeck, a former school teacher, fostered Steinbeck's love of reading and writing.
Johann Adolf Großsteinbeck, Steinbeck's paternal grandfather, had shortened the family name to Steinbeck when he immigrated to the United States. The family farm in Heiligenhaus, Mettmann, North Rhine-Westphalia, Germany, is still today named "Großsteinbeck".