She had earlier won honors in vocal competitions and the Marian Anderson Fellowship in 1943-1944.
In 1954 she became the first African American to sing a major role with the Vienna State Opera. She later also performed as a soloist with numerous European orchestras. As a concert artist, she toured throughout the United States as well as Asia, Australia and New Zealand. In 1977, she was the first African American appointed as Professor of Voice at Indiana University, and she taught there until 1997.
"My grandparents and parents were self-taught musicians; all of them sang, and there was always music in our home." Camilla's grandfather, Alexander Carey, was a choir leader and singer. "All my people sing. We were poor, but God blessed us with music." By the age of eight, Camilla was dancing, playing the piano, and singing at school and Danville's Calvary Baptist Church.
Williams trained at Virginia State College (now Virginia State University). After earning a B.S. there, she studied privately in New York, eventually with the great teacher Marion Szekely Freschl (who taught at Juilliard). She earned a Marian Anderson Fellowship in 1943 and again in 1944. She continued to receive honors in vocal competitions.
Beginning in 1944, Williams performed on the coast-to-coast RCA radio network. In 1946 she was the first African American to receive a regular contract with a major American opera company, making her debut with the New York City Opera in the title role in Puccini's Madama Butterfly. Her performance was hailed by the New York Times critic as "an instant and pronounced success." During the next six years, she performed Nedda in Leoncavallo's Pagliacci, Mimi in Puccini's La bohème, and the title role in Verdi's Aida.
Williams sang throughout the United States and Europe with various other opera companies. In 1951 she sang Bess in the landmark, first complete recording of Gershwin's Porgy and Bess.Under the baton of Lehman Engel, this recording is considered by some to be the most authentic recorded performance of the opera and brought Williams international recognition.
In 1954 she became the first African American to sing a major role with the Vienna State Opera, and performed her signature role in Madama Butterfly. In 1963, as part of the civil rights March on Washington, she sang "The Star-Spangled Banner" at the White House and before 250,000 people at the Lincoln Memorial, preceding Martin Luther King, Jr.'s "I Have a Dream" speech.
A noted concert artist, Williams toured throughout the United States, in fourteen African countries, as well as numerous countries in Asia: Formosa, South Korea, China, Japan, Laos, South Vietnam, the Philippines, New Zealand and Australia. In addition, she was a soloist with the Royal Philharmonic, BBC Symphony, Berlin Philharmonic, Vienna Symphony, Chicago Symphony, Philadelphia Orchestra and the New York Philharmonic under the direction of Leopold Stokowski. In 1950 she recorded Mahler's Symphony No. 8 with Stokowski and the New York Philharmonic.
Williams was the first African-American Professor of Voice appointed to the voice faculty of what is now known as the Indiana University Jacobs School of Music in 1977. In 1984 she became the first African-American instructor at the Central Conservatory of Music in Beijing, China. In 1997 Camilla Williams became a Professor Emerita of Voice at Indiana University Jacobs School of Music, but continued to teach privately.
From 2000 to 2011, she lived in companionship with her accompanist Boris Bazala, from Bulgaria.