Witzenberg Municipality (Afrikaans: Witzenberg Munisipaliteit; Xhosa: uMasipala wase Witzenberg) is a local municipality located within the Cape Winelands District Municipality, in the Western Cape province of South Africa. As of 2022 it had a population of 103,765.

The municipality covers an area of 10,753 square kilometres (4,152 sq mi) which includes the Land van Waveren (Tulbagh) valley, the Warm Bokkeveld, the Koue Bokkeveld and the Ceres-Karoo. It stretches from the Groot Winterhoek Mountains in the west and the Hex River Mountains in the south as far as the Northern Cape provincial border in the north and east. It abuts on the Hantam Municipality to the north, the Karoo Hoogland Municipality to the northeast, the Laingsburg Municipality to the southeast, the Breede Valley Municipality to the south, the Drakenstein Municipality to the southwest, the Bergrivier Municipality to the west and the Cederberg Municipality to the northwest.

The principal town and location of the municipal head office is Ceres on the eastern slope of the Skurweberg mountains, which as of 2011 has a population of 33,224. To the west of Ceres, on the other side of the mountains, is the Land van Waveren valley with the towns of Wolseley (pop. 12,130) and Tulbagh (pop. 8,969). To the north of Ceres is the town of Prince Alfred Hamlet (pop. 6,810), and further north, in the Koue Bokkeveld, the village of Op-die-Berg (pop. 1,531). There are a number of informal settlements: Pine Valley, Chris Hani, Mooiblom, Zibonele, Polocross, Die Gaatjie and Kleinbegin. In addition in Ward 2, Dwarsrivier, is the settlement of Romansrivier. Other settlements include: Tulbagh Road, Steinthal, Drostdy, Waterval, Kluitjieskraal, Breede River Station, and Prince Alfred Hamlet Station.

According to the 2022 South African census, the municipality had a population of 103,765 people, decreasing from 115,946 in 2011. "Coloureds" were the largest ethnic group, at 63.7% of the population, followed by "Black Africans" at 26.8% and "Whites" at 7.9%.

At the end of the apartheid era, in the area that is today the Witzenberg Municipality there were municipal councils for Ceres, Wolseley, Tulbagh and Prince Alfred Hamlet. These councils were elected by the white residents, while the coloured residents of Ceres, Tulbagh and Wolseley were governed by management committees subordinate to the white councils. The township of Nduli near Ceres had a town council established under the Black Local Authorities Act, 1982. The remaining rural areas were served by the Breërivier Regional Services Council.

While the negotiations to end apartheid were taking place a process was established for local authorities to agree on voluntary mergers. The Tulbagh municipality and management committee took part in this process, merging to form a new non-racial municipality in October 1993.

After the national elections of 1994 a process of local government transformation began, in which negotiations were held between the existing local authorities, political parties, and local community organisations. As a result of these negotiations, the existing local authorities were dissolved and transitional local councils (TLCs) were created for each town and village.

The transitional councils were initially made up of members nominated by the various parties to the negotiations, until May 1996 when elections were held. At these elections the Breërivier District Council was established, replacing the Breërivier Regional Services Council. Transitional representative councils (TRCs) were also elected to represent rural areas outside the TLCs on the District Council; the area that was to become Witzenberg Municipality included most of the Witzenberg TRC and a small part of the Matroosberg TRC.