Zingiswa Phyllis Losi (born 2 October 1975) is a South African politician and trade unionist who is currently serving as the president of the Congress of South African Trade Unions (Cosatu) since September 2018. She was formerly Cosatu's second deputy president from 2009 to 2018. She is a member of the Central Committee of the South African Communist Party (SACP) and a former member of the National Executive Committee of the African National Congress (ANC). Born in the Eastern Cape, Losi became politically active as a youth activist in the Congress of South African Students and ANC Youth League. Her first job was as a technician in the South African National Defence Force, where she served from 1996 to 1999. Between 2001 and 2014, she worked for the Ford Motor Company in Port Elizabeth, and she joined the trade union movement in 2002 as a shop steward for the National Union of Metalworkers (Numsa), a large Cosatu affiliate. She served three terms as Cosatu's second deputy president, beginning at the federation's 10th national congress in September 2009. Although she was elected to her Cosatu office as a representative of Numsa, she soon fell out with her union over her closeness with Cosatu president S'dumo Dlamini, who was a supporter of President Jacob Zuma and whose primary rival, Zwelinzima Vavi, was allied with Numsa. Losi was suspended from Numsa in September 2013, pending a disciplinary hearing, and in March 2014 she announced that she had left Ford and Numsa to work for the South African Police Service and serve as a shop steward for another Cosatu affiliate, the Police and Prisons Civil Rights Union (Popcru). On 20 September 2018, Losi was elected unopposed to succeed Dlamini, becoming Cosatu's first woman president. Her election was backed by an impressive coalition of Cosatu affiliates, including the National Union of Mineworkers and National Education, Health and Allied Workers' Union. She was re-elected to a second four-year term in September 2022.