The micropalaeontology collections, part of the larger invertebrate palaeontology and geology collections, of the Iziko South African Museum hold over 2000 specimens of Jurassic to Quaternary-aged foraminifera and ostracods, of which 436 are type specimens. These specimens represent archives that are important for research activities and the geology industry that drove the development of micropalaeontology in South Africa, with valuable contributions to hydrocarbon exploration, biostratigraphy, palaeoenvironmental studies and geology in general. The Iziko South African Museum in Cape Town is seen as the major repository for ostracod and foraminifera specimens in the country. The collections saw three periods of growth: 1) during the establishment of the Micropalaeontology Research Unit from 1989 to 1994, when much of the country’s ostracod research took place and the collection first grew; 2) through foraminifera acquisitions from 2003 to 2010 during the Honorary Associateship of Dr Ian McMillan and 3) from 2011 to 2022, when foraminiferal geochemical, palaeoceanographic and biostratigraphic research grew, contributing to southern African offshore mineral exploration and Cenozoic palaeoenvironmental studies. During the late 2010′s to 2022 the public and university students also received opportunities to learn about the importance of foraminifera in science and industry through museum activities and educational initiatives. This history of the past 36 years of growth in micropalaeontological research and collections in South Africa is evidence of the critical role that microfossil museum specimens and their associated records played in advancing geological, environmental, and palaeoceanographic sciences as well as educational opportunities.