The language policies of post-independence Namibia and Kenya provide parallels and contrasts of historical and political import concerning official English monolingualism, which both nations adopted at independence, and the more inclusive bilingual or multilingual state policies that seek to end the neglect of marginalised languages. The adoption and retention of English as the sole official language in two predominantly non-native English-speaking African states—Kenya (after 1963) and Namibia (after 1990)—are revisited in this desktop study to resuscitate language policy debates on whether multiple official languages better suit multicultural African nations. Using language planning literature and Kenya’s own volte-face which later instated Kiswahili as the nation’s co-official language in 2010, the debate is framed for analysis by the “modernization theory” of twentieth-century linguistic scholar Herder, who believed that because language reflected the unity of a people and was critical for nation-building, an official linguistic homogeneity that relegated other mediums to secondary use in official and public spaces would provide countries with “the highest potential to prosper in peace” (Beck. Language and nation in modern Namibia: The fallacies of modernization theory. In M. Putz (Ed.), Discrimination through language in Southern Africa? Perspectives on the Namibian experience (p. 215). Walter de Gruyter, 1995). Recent support for this theory by Maxwell (Nationalities Papers, 48(5), 826–842, 2020) has sought to countermand pluralistic language policies that Maxwell calls “popular primordialism” which he says, “projects national origins back into distant times”, privileging “ethnosymbolic” and “ethnonationalist” notions of language and nationhood (Maxwell. Nationalities Papers, 48(5), 829, 2020). The modernist national project saw English as a unifier against historical divisions in both Namibia and Kenya. English was also preferred over existing lingua franca: in Namibia, the use of Afrikaans especially, and its association with South African apartheid rule, and in Kenya, Kiswahili, viewed by some as having Arabic rather than indigenous African origins (Nabea. Journal of Pan African Studies, 3(1), 121–138, 2009). Were there costs to be considered in adopting the official English monolingualism policy, and did this inform Kenya’s switch to a bilingual official language policy 47 years later? What lessons might there be for the younger Namibian nation in this regard? This research parallels the debates in Namibia and Kenya especially but includes other majority non-native English-speaking contexts in the literature survey to enrich the narrative.