One of his tutors there, Edna O'Brien, became a mentor and encouraged him, saying: 'You're Black, Jewish, with a poor upbringing there are riches therein.' While working for Mobil Oil, Mosley took a writing course at City College in Harlem after being inspired by Alice Walker's book The Color Purple.

They separated 10 years later and were divorced in 2001. He moved to New York in 1981 and met the dancer and choreographer Joy Kellman, whom he married in 1987. Abandoning a doctorate in political theory, he started work programming computers. He dropped out of Goddard College, a liberal arts college in Plainfield, Vermont, and then earned a political science degree at Johnson State College. Mosley went through a 'long-haired hippie' phase, drifting around Santa Cruz and Europe. He later became more highly politicised and outspoken about racial inequalities in the US, which are a context of much of his fiction. He was largely raised in a non-political family culture, although there were racial conflicts flaring throughout L.A. He also loves Langston Hughes and Gabriel García Márquez. His mother encouraged him to read European classics from Dickens and Zola to Camus. Mosley describes his father as a deep thinker and storyteller, a 'black Socrates'. He graduated from Alexander Hamilton High School in 1970. When he was 12, his parents moved from South Central to the more comfortable, working-class west LA. For $9.50 a week, he attended the Victory Baptist day school, a private African-American elementary school that held pioneering classes in black history. Mosley was an only child, and ascribes his writing imagination to 'an emptiness in my childhood that I filled up with fantasies'. His parents tried to marry in 1951 but, though the union was legal in California, where they were living, no one would give them a marriage license.

He had worked as a clerk in the segregated US army during the Second World War. His father, Leroy Mosley (1924–1993), was an African American from Louisiana who was a supervising custodian at a Los Angeles public school. His mother, Ella ( née Slatkin), was Jewish and worked as a personnel clerk her ancestors had immigrated from Russia. Mosley was born in Los Angeles, California. In 2020, Mosley received the National Book Foundation Medal for Distinguished Contribution to American Letters, making him the first Black man to receive the honor. He has written a series of best-selling historical mysteries featuring the hard-boiled detective Easy Rawlins, a black private investigator living in the Watts neighborhood of Los Angeles, California they are perhaps his most popular works. Walter Ellis Mosley (born January 12, 1952) is an American novelist, most widely recognized for his crime fiction. National Book Foundation Medal for Distinguished Contribution to American Letters

White Butterfly by Walter Mosley