T. Ras Makonnen (c. 1900- 18 December 1983, Nairobi) was a Guyanese-born Pan-African activist.
Makonnen was born George Thomas N. Griffiths in Buxton, Guyana. His paternal grandfather was reputedly born in Tigre, Ethiopia, and taken to British Guiana by a Scottish miner. Makonnen completed his secondary school in Guyana, before leaving in 1927 to study mineralogy in Texas, and then attended Cornell University in 1933. During the Second Italo-Abyssinian War in 1935, he changed his name to emphasize his African roots. He has three children: T'Shai R. Makonnen, Desta Makonnen and Sheba Makonnen.
Makonnen went to the Royal Agricultural College in Copenhagen, Denmark, and spent 18 months in that country, until he was deported for publishing an article that claimed that Denmark was producing the mustard gas being used to kill civilians in the Italian invasion of Ethiopia. Makonnen subsequently settled in London in 1937. He became an active member of the International African Service Bureau that had formed under George Padmore's leadership. Writing about Makonnen's role in the Bureau, historian Carol Polsgrove presents him as the group's business manager, selling its journal, International African Opinion, at political meetings and handling the bills.
After the outbreak of the Second World War Makonnen moved to Manchester, where he studied history at Manchester University. True to his entrepreneurial spirit, he opened four restaurants, the profits from which went towards his political work. He continued to be active in the International African Service Bureau (IASB) and, along with George Padmore and the Gold Coast's Kwame Nkrumah, helped organize the fifth Pan-African Congress in 1945. He also hosted visitors from Africa and opened a bookstore and a mail-order book service. In 1947 he started a new publication, Pan-Africa, which he hoped would be "a reflection of the everyday life and deeds of the African people". He distributed it across Africa and the Americas, but it was hard to collect fees, and in some places bookstores and subscribers were nervous about being seen with what was then, under colonial rule, a politically suspect publication. The periodical ceased publication the year after it began.