Thandiwe Nelly Mpambani grew up in Sophiatown, the daughter of a shoemaker and a domestic worker. When she was a teenager, she was attacked with petrol and matches and her face was permanently scarred. Her career as a singer and dancer began in the mid-1950s.
Klaasen was awarded the Order of Ikhamanga in Silver (2006) for "excellent achievement in and contribution to the art of Music". In August 2013, as part of the Women's Month celebrations, Klaasen and four other icons of South African jazz - Abigail Kubeka, Dorothy Masuka, Sathima Bea Benjamin and Sylvia Mdunyelwa - were honoured by Standard Bank with lifetime achievement awards. Other awards she has received include the Woman of Distinction Award received in Canada (1999), and a lifetime achievement award at the 2006 South African Music Awards.
- Thandi Klaasen profile Archived 4 March 2016 at the Wayback Machine
- Kagiso Msimango, "Warrior Goddess: Thandi Klaasen", The Goddess Academy, 20 May 2006.
- South African History Online, sahistory.org.za; accessed 15 January 2017.
- Notice of death of Thandi Klaasen, channel24.co.za; accessed 15 January 2017.
- "Standard Bank Joy of Jazz honours legends of Jazz", SABC, 11 August 2013.
- Thandi Klaasen biography at Festival International Nuits d'Afrique, Montréal Festimania.