Bellah was born in Altus, Oklahoma, on February 23, 1927. His father was a newspaper editor and publisher who committed suicide when Bellah was three years old. His mother Lillian moved the family to Los Angeles, where she had relatives. Bellah grew up in Los Angeles and attended Los Angeles High School, where he and his future wife, Melanie Hyman, were editors of the student newspaper. They got married in 1948 after she graduated from Stanford University, and he began studying at Harvard University after a service in the US Army. Bellah's wife died in 2010.