Diabi Jacob Mmualefe (born 28 March 1958) is a Botswana diplomat and is currently the Ambassador to Brazil with concurrent accreditation to Argentina, Chile, Guyana, Venezuela and CARICOM.
He was the First Secretary at the Embassy of Botswana in Addis Ababa, Ethiopia, Counsellor at the Embassy of Botswana in Stockholm, Sweden and later on the Botswana High Commission in London, United Kingdom. He held positions at Botswana's Ministry of Foreign Affairs before his ambassadorial appointment.