The study investigates the role of Divalent Metal Transporter 1 (DMT1) in regulating mitochondrial iron translocation and metastatic outgrowth in triple-negative breast cancer (MDA-MB-231) cells. DMT1 is found to mediate transient "kiss-and-run" interactions between early endosomes (EE) and mitochondria, facilitating mitochondrial iron translocation. Silencing DMT1 in MDA-MB-231 cells reduces these interactions, leading to decreased mitochondrial iron translocation, increased labile iron pool (LIP) levels, and altered mitochondrial bioenergetics. Additionally, DMT1 silencing activates PINK1/Parkin-dependent mitophagy and disrupts the aggregation of 3D multicellular tumor spheroids. In vivo lung metastasis assays show that DMT1 silencing promotes the outgrowth of lung metastatic nodules in both human and murine models of triple-negative breast cancer. These findings highlight a DMT1-dependent pathway connecting EE-mitochondria interactions to mitochondrial iron translocation and metastatic fitness in breast cancer cells.The study investigates the role of Divalent Metal Transporter 1 (DMT1) in regulating mitochondrial iron translocation and metastatic outgrowth in triple-negative breast cancer (MDA-MB-231) cells. DMT1 is found to mediate transient "kiss-and-run" interactions between early endosomes (EE) and mitochondria, facilitating mitochondrial iron translocation. Silencing DMT1 in MDA-MB-231 cells reduces these interactions, leading to decreased mitochondrial iron translocation, increased labile iron pool (LIP) levels, and altered mitochondrial bioenergetics. Additionally, DMT1 silencing activates PINK1/Parkin-dependent mitophagy and disrupts the aggregation of 3D multicellular tumor spheroids. In vivo lung metastasis assays show that DMT1 silencing promotes the outgrowth of lung metastatic nodules in both human and murine models of triple-negative breast cancer. These findings highlight a DMT1-dependent pathway connecting EE-mitochondria interactions to mitochondrial iron translocation and metastatic fitness in breast cancer cells.