Recurrent pregnancy loss (RPL) is a troubling condition that affects couples worldwide. Despite extensive research efforts, many RPL cases remain unexplained, highlighting the need for novel approaches to unravel its underlying mechanisms. Recent advances in microbiome research have shed light on the potential role of the microbiome in reproductive health and outcomes. Based on a systematic literature research, this review aims to comprehensively explore the current understanding of the microbiome's involvement in RPL, focusing on the vaginal, endometrial, and gut microbiomes. Evidence from the available studies is examined to explain the relationship between the microbiome and RPL. Furthermore, we discuss the diagnostic potential of the microbiome, therapeutic interventions, and future directions in microbiome research for RPL. Understanding the complex interactions between the microbiome and reproductive health holds promise for developing targeted interventions to help patients today diagnosed as unexplained.