This study investigates the role of osteocytes in bone metastasis and their ability to inhibit tumor development. Osteocytes, the most abundant cells in the bone microenvironment, were found to transfer mitochondria to metastatic cancer cells, triggering a cGAS/STING-mediated antitumor response. The transfer of mitochondria was mediated by Miro1 and MFN2, and its inhibition through genetic knockout impaired tumor immunogenicity, leading to increased bone metastasis progression. Osteocyte mitochondria increased cytosolic mtDNA levels in cancer cells, activating the cGAS/STING pathway and enhancing tumor immunogenicity. This study provides evidence of a novel mechanism by which osteocytes communicate with cancer cells, offering potential therapeutic strategies for preventing bone metastasis.This study investigates the role of osteocytes in bone metastasis and their ability to inhibit tumor development. Osteocytes, the most abundant cells in the bone microenvironment, were found to transfer mitochondria to metastatic cancer cells, triggering a cGAS/STING-mediated antitumor response. The transfer of mitochondria was mediated by Miro1 and MFN2, and its inhibition through genetic knockout impaired tumor immunogenicity, leading to increased bone metastasis progression. Osteocyte mitochondria increased cytosolic mtDNA levels in cancer cells, activating the cGAS/STING pathway and enhancing tumor immunogenicity. This study provides evidence of a novel mechanism by which osteocytes communicate with cancer cells, offering potential therapeutic strategies for preventing bone metastasis.