This article addresses the diplomacy practiced by Sir Stanley Rous, Fédération Internationale de Football Association (FIFA) president (1961–1974), and the international history of Democratic People’s Republic of Korea involvement in, and the boycott by African nations of, the 1966 World Cup in light of a number of newly available primary sources. The new materials reveal first, Rous’s diplomatic practice and the tension between formal and informal diplomacy he pursued; and second, the disquiet in London over North Korean participation, a problem relieved in great part by Rous’s interventions. Concerns over anthems, protocol, and flags were mediated by Rous as he negotiated with the British foreign policy-making establishment from his position as FIFA president. The analysis illuminates the negotiation, representation and communication underpinning the diplomacy of the 1966 World Cup. Rous was also influential, though to contrasting effect, in the case of the opposition of the Confédération Africaine de Football (CAF) to apartheid in South Africa and CAF’s support for the emerging pan-African cause. The article offers new insights into the diplomatic role of Rous and FIFA and throws light upon the tension between formal and informal diplomatic practices underlying the staging of a global tournament in the 1960s amid the dual pressures of the Cold War and an emerging pan-Africanism.