Two new species of Nixonia Masner (Hymenoptera, Platygastridae, Scelioninae), Nixonia masneri sp. n. and Nixonia mcgregori sp. n. are described from South Africa and further records of Nixonia corrugata Johnson & Masner, Nixonia lamorali Johnson & Masner, Nixonia stygica Johnson & Masner are documented. Johnson and Masner’s 2006 identification key is modified to include the newly described species. Online interactive Lucid matrix and Lucid Phoenix dichotomous keys are available on WaspWeb at http://www.waspweb.org/Platygastroidea/Keys/index.htm. Lucid data files in lif and sdd format are available at: doi:10.3897/zookeys.20.112.app.1.ik and doi:10.3897/zookeys.20.112.app.2.ik.