As the largest organ of the human body, the skin serves as the primary barrier of the immune system against external environmental challenges. However, it is frequently subjected to problems such as aging, inflammation, hyperpigmentation, and neoplastic diseases. In recent years, probiotics have gained significant attention for their potential to improve skin health, demonstrating antioxidative, anti-inflammatory, skin matrix-preserving, and melanogenesis-regulating properties. Research on the bioactive components and mechanisms of probiotics has shown substantial progress, primarily through the modulation of skin microbiota balance, enhancement of barrier function, suppression of inflammatory responses, and regulation of melanin synthesis. Studies indicate that specific probiotic strains can mitigate oxidative stress and inflammatory responses, thereby delaying skin aging, alleviating symptoms of atopic dermatitis and acne, and reducing pigmentation by inhibiting tyrosinase activity. This review summarizes the mechanisms and applications of probiotics in skin health. It discusses their prospects in clinical therapy and daily skincare, providing valuable insights for further research and product development in this field.