Mallodon downesi is a species of beetle belonging to the family Cerambycidae.

The colours range from dark brown to black.

Antennae are quite short in comparison with other species in the family.

Main host plants are Acacia polyacantha, Cananga odorata, Canarium schweinfurthii, Cocos nucifera, Daniellia oliveri, Delonix regia, Hevea brasiliensis, Khaya anthotheca, Persea americana, Spondias mombin, Spondias purpurea, Sterculia tragacantha, Tamarindus indica and Theobroma cacao.

This species is widespread throughout the Afrotropical and Madagascan regions (Angola, Benin, Botswana, Burundi, Cameroon, Central African Republic, Comoros, Democratic Republic of the Congo, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Kenya, Liberia, Madagascar, Mali, Mozambique, Namibia, Nigeria, Republic of the Congo, Rwanda, São Tomé and Príncipe, Senegal, Sierra Leone, South Africa, Tanzania, Togo, Uganda, Zambia and Zimbabwe).