The West African mangrove ecosystems are home to Avicennia africana P. Beauv., also known as black mangrove, which is renowned for its ecological and traditional therapeutic significance. This chapter aims to explore and review the bioactive compounds found in A. africana and their associated biological activities. Key bioactive compounds identified include phenolic compounds, flavonoids (like apigenin, kaempferol, luteolin, and quercetin), terpenoids (including limonene, pinene, farnesol, and phytol), along with alkaloids, saponins, tannins, and sterols. These compounds show significant biological actions, which include anti-inflammatory, antioxidant, anticancer, antimalarial, and antimicrobial effects. The antioxidant activity mitigates oxidative stress, while anti-inflammatory properties reduce inflammation. The anticancer effects involve cell cycle regulation and apoptosis induction, and antimicrobial activities target bacteria, fungi, and viruses. Furthermore, these compounds potentially possess nutraceuticals, pharmaceuticals, and cosmeceutical applications that may contribute to health and wellness through dietary supplements, new drug development, and skincare products. The findings underscore A. africana as a significant source of natural bioactive agents, with promising prospects for future research and industrial applications.