Effective conservation efforts and predictions of future impacts on biodiversity depend heavily on publicly available information about species distributions. However, data on species distributions is often patchy, especially in many countries of the Global South where resources for biological surveys have been historically limited. In this study, we use biodiversity ignorance scores to quantify and visualize gaps and biases in biodiversity data for Namibia, with a focus on five terrestrial taxa at a spatial scale of 10 x 10 km. We model the relationship between ignorance scores and socio-geographical variables using generalized additive models for location, scale and shape (GAMLSS). Our findings demonstrate that despite a high volume of occurrence records available on the Global Biodiversity Information Facility (GBIF), publicly available knowledge of Namibia's terrestrial biodiversity remains very limited, with large areas contributing few or no records for key taxa. The exception is birds that have benefitted from a massive influx of data from the citizen science platform eBird. Our study also highlights the importance of citizen science initiatives for biodiversity knowledge and reinforces the usefulness of ignorance scores as a simple intuitive indicator of the relative availability and distribution of species occurrence records. However, further research, biological surveys, and renewed efforts to make existing data held by museums and other institutions widely available are still necessary to enhance biodiversity data coverage in countries with patchy data. Keywords: GBIF, occurrence records, Survey effort, Ignorance scores, Species distributions, Vertebrates, Southern Africa.