In this study, 31 species of noctuid stemborers belonging to the genus Sesamia Guenée, 1852 (Lepidoptera: Noctuidae: Noctuinae: Apameini: Sesamiina) are reviewed. All these species are assigned to the Sesamia cretica group sensu Tams & Bowden (1953). Based on genitalic characters, several subgroups are hereby defined. Nine species belong to a species complex defined as the Sesamia albivena Hampson, 1902 subgroup; it consists of S. albivena, S. mocoensis Tams & Bowden, 1953, n. stat., S. sudanensis Tams & Bowden, 1953, n. stat. S. taenioleuca (Wallengren, 1863), and of five new species that are described (S. aethiopica n. sp. from Ethiopia, S. kafulo n. sp. from Botswana and Zambia, S. kavirondo n. sp. from Kenya and Uganda, S. maloukou n. sp. from Republic of Congo, and S. soyema n. sp. from Ethiopia. Four species belong to a species complex that defined as the Sesamia cretica subgroup; it encompasses S. cretica, S. rufescens Hampson, 1910, and two new species that are described (S. ihambane n. sp. from Mozambique and Tanzania and S. kikuyuensis n. sp. from Kenya); two new synonyms are introduced for Sesamia cretica: Nonagria uniformis Dudgeon 1905 n. syn. and Sesamia griselda Warren, 1913, n. syn.. Ten species belong to a species complex defined as the Sesamia fuscifrontia Hampson, 1914 subgroup; it includes S. fuscifrontia, S. geyri (Strand, 1915) and eight new species that are described (S. babati n. sp. from Tanzania, S. babessi n. sp. from Cameroon and Zambia, S. mabira n. sp. from Uganda, S. nangaensis n. sp. from Cameroon and Republic of Congo, S. rungwa n. sp. from Tanzania, S. simillima n. sp. from Benin, Cameroon, Kenya and Uganda, S. taveta n. sp. from Kenya and S. ulaukae n. sp. from Ethiopia). One species belongs to a species complex defined as the Sesamia salama n. sp. subgroup; it consists of S. salama n. sp. from Kenya and another undescribed Sesamia species from South Africa. One species belongs to a species complex defined as the Sesamia viettei Rungs, 1954 subgroup. Six species belong to a species complex defined as the Sesamia wiltshirei Rungs, 1963 subgroup; it groups S. wiltshirei and five new species that are described (S. djenoensis n. sp. from Republic of Congo, S. inexpectata n. sp. from South Africa and Zambia, S. lefini n. sp. from Republic of Congo, S. echinochloa n. sp. from Botswana, Kenya, Mozambique, South Africa, Tanzania and Zambia and S. rindini n. sp. from Tanzania). A supplemental description of the previously described species is also provided. Novel host plant records are also provided for 11 species of the S. cretica group. To complement the morphological study, both phylogenetic and molecular species delimitation analyses were carried out on a multimarker (four mitochondrial and two nuclear genes) molecular dataset encompassing 144 specimens representing 35 species (including 25 species from the S. cretica group). Molecular analyses provide a well-supported phylogenetic framework for the species of interest, which are all recovered monophyletic. Molecular species delimitation analyses also support the species status of almost all sampled species. Interestingly, the inferred tree indicates that the S. cretica group and the S. fuscifrontia subgroup are both paraphyletic; this indicates that, while highly informative, the chosen genitalic characters in Sesamia are not all synapomorphies.