This research reconstructed paleoclimatic and paleoenvironmental conditions using proxy data derived from cave stalagmites, an aeolian sand ramp and fluvial slackwater deposits (SWDs) in Namibia and Madagascar, a broad region influenced by a wide variety of atmospheric and oceanic circulation systems. The stalagmites provided accurately dated high-resolution multiproxy records of Holocene hydroclimate variations in northwest Madagascar and northern Namibia. An 8260-yr stalagmite record for northwest Madagascar documents multiple significant droughts in the Holocene and offers insights into the causes of megafaunal extinctions on the island over the last 2000 years. Three stalagmite records from northern Namibia record climate variations in northwest and northcentral Namibia over the past 4000 years. Comparison of the northern Namibia stalagmite data suggests that there were changes in the influence of Atlantic versus Indian Ocean moisture during the Holocene depending on the dynamics of the Congo Air Boundary. The sedimentology of a sand ramp in the Konkiep valley of southern Namibia, dated by 11 optically stimulated luminescence (OSL) ages, revealed periods of strong winds and great aridity at 49-29 ka and 24-15 ka, and less windy and wetter conditions with fluvial activity at 24-29 ka. Slackwater deposits on the Namibian side of the Orange River, dated by OSL, provided a record of major floods in the lower Orange River at 6.8-8 ka, 5.3-6.5 ka, 3.4-4.6 ka, and 0.5-1.2 ka, indicating increased summer rainfall in the interior of Southern Africa at these times. These records are compared with other published evidence of climate change in southern Africa and Madagascar. The records are also compared with major climate events in the Northern Hemisphere to see how the Southern Hemisphere tropics and subtropics responded to changing conditions in the Northern Hemisphere. The records derived from this research greatly improve our understanding of the late Quaternary paleoclimate of southern Africa and Madagascar, and make important contributions to the southern hemisphere paleoclimate database.