Sanchez was born in Birmingham, Alabama, on September 9, 1934 to Wilson L. Driver and Lena Jones Driver. Her mother died when Sanchez was only one year old, so she spent several years being shuttled back and forth among relatives. One of those was her grandmother, who died when Sanchez was six. The death of her grandmother proved to be a trying time in her life. Though only six, Sanchez suffered from losing her loved one, developing a stutter that contributed to her becoming introverted. However, her stutter only caused her to read more and more and pay close attention to language and its sounds.

In 1943, she moved to Harlem to live with her father (the school teacher), her sister, and her stepmother, who was her father’s third wife. When in Harlem, she learned to manage her stutter and excelled in school, finding her poetic voice which later emerged during her studies at Hunter College. Sanchez focused on the sound of her poetry, admitting to always reading her poetry aloud, and received praise for her use of the full range of African and African-American vocal resources. She is known for her sonic range and dynamic public readings. She now terms herself as an “ordained stutterer.” Sanchez earned a BA in political science in 1955 from Hunter College.

Sanchez taught 5th Grade in NYC at the Downtown Community School, until 1967. She has taught as a professor at eight universities and has lectured at more than 500 college campuses across the US, including Howard University. She was also a leader in the effort to establish the discipline of Black Studies at the university level. In 1966, while teaching at San Francisco State University she introduced Black Studies courses. Sanchez was the first to create and teach a course based on Black Women and literature in the United States and the course she offered on African-American literature is generally considered the first of its kind taught at a predominately white university. She viewed the discipline of Black Studies as both a new platform for the study of race and a challenge to the institutional biases of American universities. These efforts are clearly in line with the goals of the Black Arts Movement and was a known black feminist. Sanchez was the first Presidential Fellow at Temple University, where she began working in 1977. There, she held the Laura Carnell chair until her retirement in 1999. She is currently a poet-in-residence at Temple University. She has read her poetry in Africa, the Caribbean, China, Australia, Europe, Nicaragua, and Canada.

The aim of the Black Arts Movement was a renewal of black will, insight, energy, and awareness. Sanchez published poetry and essays in numerous periodicals in the 1960s, including The Liberator, Negro Digest, and Black Dialogue. Her writing established her importance as a political thinker to the “black aesthetic” program. Sanchez gained a reputation as an important voice in the Black Arts movement after publishing the book of poems Home Coming in 1969. This collection and her second in 1970, titled We a BaddDDD People demonstrated her use of experimental poetic forms to discuss the development of black nationalism and identity.

In 1969, Sanchez was awarded the P.E.N. Writing Award. She was awarded the National Education Association Award 1977–1988. She won the National Academy and Arts Award and the National Endowment for the Arts Fellowship Award in 1978–79. In 1985, she received the American Book Award for Homegirls and Handgrenades. She has also been awarded the Community Service Award from the National Black Caucus of State Legislators, the Lucretia Mott Award, the Governor’s Award for Excellence in the Humanities, and the Peace and Freedom Award from the Women’s International League for Peace and Freedom, as well as the 1999 Langston Hughes Poetry Award, the 2004 Harper Lee Award, and the 2006 National Visionary Leadership Award. In 2009, she received the Robert Creeley Award, from the Robert Creeley Foundation.

In 1972, Sanchez joined the Nation of Islam, during which time she published A Blues Book for Blue Black Magical Women (1974), but she left the organization after three years in 1975 because their views on women’s rights conflicted. She continues to advocate for the rights of oppressed women and minority groups. She wrote many plays and books that had to do with the struggles and lives of Black America. Among her plays are Sister Son/ji, which was first produced Off-Broadway at the New York Shakespeare Festival Public Theater in 1972; Uh, Huh: But How Do it Free us?, staged in Chicago at the Northwestern University Theatre in 1975, and Malcolm Man/Don’t Live Here No Mo’, first produced in 1979 at the ASCOM Community Center in Philadelphia. Sanchez has edited two anthologies of Black literature: We Be Word Sorcerers: 25 Stories by Black Americans (1974) and 360° of Blackness Coming at You (1999). She is also committed to a variety of activist causes, including the Brandywine Peace Community, MADRE, and Plowshares.

In 2013 Sanchez headlined the 17th annual Poetry Ink at which she read her poem “Under a Soprano Sky”.

BaddDDD Sonia Sanchez, a documentary film by Barbara Attie, Janet Goldwater and Sabrina Schmidt Gordon, spotlighting Sanchez’s work, career, influence and life story, was released in 2015 when it was shown at the Full Frame Documentary Film Festival The film premiered in the UK on June 22, 2016, at Rivington Place.

In 2017 Sanchez was honored at the 16th Annual Dr. Betty Shabazz Awards in a ceremony held on June 29 at the Schomburg Center for Research in Black Culture, Harlem.

In 2018, she won the Wallace Stevens Award from the Academy of American Poets for proven mastery in the art of poetry.

At the 84th Annual Anisfield-Wolf Book Awards ceremony on September 26, 2019, Sanchez was honored with the Lifetime Achievement Award by the Cleveland Foundation.