MEC Themba Mthembu was born in Inanda in 1958 in a working class family. His father was a dock worker and his mother a domestic worker. MEC Mthembu received his schooling in KwaMashu and then went on to qualify as a Chemical Engineering Technician from the Mangosuthu University of Technology. This led to work as an engineering technician in the chemical industry and his involvement in the trade union movement.
MEC Mthembu cut his teeth in politics by becoming a student activist in the 70's and early 80's. This led to his involvement in the struggle for liberation working in the underground cells structures.
Since South Africa became a democracy, he has been in various leadership positions both in the ANC and SACP. He has been the Provincial Secretary of the SACP since 2002 and sits in its Central Committee. He joined the legislature in 2009 and was appointed as Chairperson of the Agriculture Portfolio Committee, a position he held until he was appointed MEC for the KwaZulu-Natal Department of Agriculture and Rural Development