Background: Botryococcus braunii is well known from all continents, but it has been sparsely recorded from Africa compared to other continents. The alga recently formed a rusty orangered bloom in the Tilda Viljoen Dam, situated near Gobabis in Namibia. Blooms of this species are known to produce allelopathic substances that inhibit the growth and diversity of other phytoplankton, zooplankton and fish. Objectives: The objective of this study was to record the presence of B. braunii in Namibia. Method: Morphological features of the species were compared with illustrations and literature on B. braunii found in other continents of the world, particularly North America and Europe. Extensive literature surveys revealed its currently known geographical distribution. Results: The organism responsible for the discolouration of the water was identified as B. braunii. Microscopic examination revealed large colonies that floated in a thick layer on the surface of the water. Literature searches on the geographical distribution of B. braunii revealed that this was the first record of this species' presence in Namibia. Conclusion: The known geographical distribution of B. braunii was expanded to include Namibia.