Madlanga was born in 1962 in Njijini village, Mount Frere, to a family of the amaBhaca.[1][2] He attended Lekete High School in Acornhoek.[2] His father, a teacher, encouraged him to apply for a bursary to read law at the University of Transkei, where he completed a BJuris in 1981 in an atmosphere of growing social unrest.[2] During his final year he began working in a magistrate's office, though he was close friends with African National Congress activists under investigation by his colleagues.[2]
On 1 August 2013, Madlanga was appointed permanently to the Constitutional Court, replacing Zak Yacoob.[7] His appointment had been widely expected, especially after he impressed at his interview before the Judicial Service Commission (on which Madlanga had served since 2010), though some felt a woman ought to have been appointed.[6][8] The Judicial Service Commission questioned him on his 1998 judgment in Bangindawo v Head of the Nyanda Regional Authority,[9] in which he had held controversially that there was "no reason whatsoever for the imposition of the western conception of the notions of judicial impartiality and independence in the African customary law setting".[10] Madlanga admitted at the interview that this judgment was wrong.[8]
Madlanga's first judgment for the Constitutional Court was Gaertner v Minister of Finance, on the right to privacy and search and seizure.[11] In March 2014, he wrote a 94-paragraph judgment dismissing Uruguayan businessman Gaston Savoi's challenge to his prosecution on charges of corruptly procuring a contract from the KwaZulu-Natal government.[12][13] A year later, Madlanga delivered the controversial main judgment in Paulsen v Slip Knot, which removes an exception to the in duplum rule.[14] This judgment was described as "consumer friendly",[15] but marked a "sea change" for South African banking practice,[16] and was strongly criticised extra-curially by Malcolm Wallis.[17] Madlanga's next judgment for the Court was DE v RH, which abrogated the action for adultery.[18] Madlanga was one of the authors of the majority judgment in the 2015 My Vote Counts v Speaker,[19] which was widely condemned.[20][21]