This study examines Moroccan-Ottoman rapprochement during the second half of the eighteenth century, with particular attention to the reign of Moulay Muhammad ibn Abd Allah (1757-1790) and its repercussions for the Regency of Algiers. It adopts a historical-analytical approach and draws on Ottoman Hatt-i Humayun documents together with Moroccan and Algerian historical sources. The study shows that this rapprochement was not based on religious considerations alone. It was also linked to shared political, military, and economic interests. Its effects on the Regency of Algiers were twofold. It contributed to efforts to address the question of captives. At the same time, it strengthened the Regency's determination to protect its frontiers and preserve its sovereign independence.