Billy Masetlha was born on 21 November 1954 in Alexandra, Johannesburg, Transvaal (now Gauteng). He is a founder member of the Congress of South African Students (COSAS) and participated in the formation of the Azanian Student's Organisation (AZASO) in 1979. Prior to that, he was a member Soweto Student's Representative Council in 1976.
He was arrested for furthering the aims of the African National Congress (ANC). In 1976 Masetlha joined uMkhonto we Sizwe (MK). He went into exile to Zambia in 1979 and joined the external mission of the ANC, specialising in youth and student organisations. He was instrumental in the formation of the Johannesburg Democratic Action Committee (JODAC).
Masetlha is the Former Director- General of the South African National Intelligence Agency. He has also served as a Presidential Advisor. He was elected at number 43 as a Member of the ANC’s National Executive Committee (NEC) at its 53rd National Conference in Mangaung, Bloemfontein, Free State Province, in December 2012.
Former President Thabo Mbeki fired Masetlha from his post as Director-General of Intelligence in 2006. Masetlha was blamed for authorising the unlawful surveillance of ANC executive member Saki Macozoma under the pretext that he was involved with foreign intelligence; for being involved in the fabrication of the e-mails that purported to implicate senior government and ANC officials in a plot to side-line and incriminate embattled former Deputy President Jacob Zuma; for being highly involved in party political squabbles by colluding with politicians in the divisive succession battle that, at the time, was polarising the ruling party between Mbeki and Zuma camps; and for acting unlawfully in bugging and intercepting individuals’ communications for the same purpose, which could have contributed to the fabrication of the e-mails. Masetlha took the matter to court and in court papers, called Mbeki a liar in return but lost that battle when his dismissal was confirmed by the Constitutional Court.
In 2007, Masetlha was acquitted in the Hatfield Community Court Magistrate of charges of contravening the Intelligence Service Oversight Act for allegedly withholding information from Inspector General of Intelligence Zolile Ngcakani.
In 2011, in a Mail and Guardian report, it was stated that Masetlha became the first senior ANC member to openly say that an alleged plot to oust Zuma as ANC president in 2012 was real.