Leo Linda Sihlali was born on 9 September 1915 in Butterworth. He went to primary school in Tarkastad where his mother worked as a teacher. On completion he went to Lovedale to commence his secondary school education. Sihlali then enrolled at the University of Fort Hare for his tertiary education, and also later received a Bachelor of Arts degree from the University of South Africa (UNISA).
In the 1940s Sihlali contributed to the regeneration of the All Africa Convention (AAC), and was instrumental in contributing to the programs and activities of the NEUM. Through the Cape African Teachers Association (CATA), he fought to integrate the struggle for education with the struggle against Apartheid. Thus, Sihlali played a role in affiliating Cape African Teacher’s Association (CATA) to the AAC. He was active in organizing the boycott campaign launched by the Non European Unity Movement (NEUM) against White Native representatives, and support peasant struggles in the Transkei against betterment policies imposed by the government.
Sihlali became part of the delegation of the AAC to the NEUM Conference where he delivered a paper on ‘Land Hunger’. In December 1951 he participated in a meeting of CATA and the Teacher’s League of South Africa (TLSA) which resulted in the formation of the Cape Teachers Federal Council.Sihlali was elected as the council’s first president.Between 1951 and 1953 he also served as President of the CATA, and from 1953 to 1955 he was editor of the ‘Teacher’s Vision’,an official publication of CATA.
In 1952 Sihlali alongside A.C Jordan, Livingstone Mqotsi, N Honono and ZK Mzimba, among others, vigorously campaigned against recommendations of the Eiselen Commission in African Education. On 30 September 1955, the entire CATA Executive members were dismissed including Sihlali as part of the government’s attempt to intimidate CATA members. As a result of the loss of his income, Sihlali was forced to work as a shop assistant in Queenstown, while continuing his work with peasant originations like Kongo, Transkei Organised Bodies, Glen Grey Stock Rate Association. In 1956 he was elected as General Secretary of the AAC. The following year he was forced to flee the country to Bechuanaland (Botswana) as a result of threats to his life by the government for his fierce opposition to Bantu Authorities. He worked briefly as a teacher and returned to South Africa and resumed underground work for Unity Movement in Johannesburg, Natal and the Cape.
Sihlali was appointed as fulltime organiser of the AAC in 1958. He was the founder member of the African People’s Democratic Union of Southern Africa (APDUSA) at its formation in 1961. He was elected President of the NEUM in 1962. A year later in 1963 he was banned and placed under house arrest by the government. When the government launched a series of arrests of leading figures of the NEUM in 1964, Sihali was arrested. As a result of this constant harassment by the government he, together with Louis Mtshizana, attempted to skip the country and go into exile. Both were arrested at Koster on their way to Botswana and charged under the Suppression of Communism Act and with attempting to leave the country illegally. Sihlali was sentenced to five years* in prison which he served on Robben Island.
After his release, he found work as a teacher, but a year later he was arrested and detained for year. The government attempted to force him to testify against 14 other APDUSA members’ cadres, but Sihlali refused. When he was released from detention he found work as a teacher and moved around a number of times teaching in Mount Hargreaves, Osborne, Nyanga, Ntlaza, Huka and finally Mount Frere. He was elected as the President of the Transkei Teachers' Association and represented this association in the Council of the University of the Transkei.
Sihlali remained active in the Unity Movement and in the community until his death on 20 March 1989.