The Nelson Mandela Bay Municipality (Xhosa: uMasipala oMbaxa iNelson Mandela Bay; Afrikaans: Nelson Mandelabaai Metropolitaanse Munisipaliteit) is one of eight metropolitan municipalities in South Africa. It is located on the shores of Algoa Bay in the Eastern Cape province and comprises the city of Gqeberha (Port Elizabeth), the nearby towns of Kariega (Uitenhage) and Despatch, and the surrounding rural area.

The name "Nelson Mandela Bay Metropolitan Municipality" was chosen to honour former President Nelson Mandela.

Bricks used in the Nelson Mandela Bay Metropolitan Municipality around 1903–04 may have been made from parts of the holotype of the sauropod dinosaur Algoasaurus bauri.

Established on 5 December 2000, the Nelson Mandela Bay Metropolitan Municipality was formed as an administrative area covering Gqeberha (Port Elizabeth), the neighbouring towns of Kariega (Uitenhage) and Despatch and the surrounding agricultural areas. Thus included the following cities/towns/villages:

As of the census of 2011, there are 1,152,115 people and 324,292 households in the Nelson Mandela Bay Metropolitan Municipality.

In the 2007 census, 60.4% of respondents described themselves as Black African, 22.6% Coloured, 16.1% White and 0.9% Indian/Asian.

The largest religious groupings are Christian (89.4% of residents), no religion (6.1%), Muslim (1.5%), Jewish (0.4%) and Hindu (0.3%).

57.3% of the residents speak Xhosa as their mother tongue. Afrikaans is the mother tongue of 29.7%, and English, 12.1%.