Numerous studies have revealed how Lexical Cohesion supported the fulfilment of political leaders’ persuasion intention in their rhetoric. The purpose of this study was to cross-culturally explore President Obama’s and President Buhari’s Inaugural Speeches to examine the impact of culture on the persuasive functions of Lexical Cohesion in their rhetoric. Therefore, while drawing on Pragmatics, the study adopted a qualitative discourse analysis approach, utilised an eclectic framework of Lexical Cohesion based on Hoey (1991), Martin (1992) and Eggins (2004) to analyse Obama’s and Buhari’s first inaugural speeches. The findings indicate, on one hand, that although Obama deployed more categories and more frequencies of Lexical Cohesion than Buhari did, ‘Repetition’ (50%) was the most dominant source of Lexical Cohesion in each of the two speeches. Moreover, the most reiterated item in the two speeches were personal pronouns, where Obama mostly repeated the pronoun ‘we’, which had inclusive function, and Buhari mostly repeated ‘I’ and the exclusive ‘we’. On the other hand, the findings suggest that Obama utilised Lexical Cohesion mainly for ‘emotional appeals’, ‘audience involvement’, and ‘credibility-building strategies’; while Buhari used Lexical Cohesion for ‘emphasizing his (and his team’s) personal commitment’, ‘building his credibility’, and ‘demonizing past administrations’. Finally, in the light of these findings, the study has drawn two major conclusions: (1) that on the preponderance of repetition of personal pronouns in both the two speeches, the findings suggest that the generic conventions of the use of personalised English in the inaugural address outweigh any culture-specific discourse practices of the two communities; (2) that Obama’s strategies of emotional appeals and audience involvement that enabled him to ‘speak along with his audience’, which contrast with Buhari’s strategies of emphasizing personal commitment and audience-exclusive tone that made him to ‘speak alone’, seem to have rendered Obama’s speech more interactional and more audience-engaging than Buhari’s speech.