Metastasis, the spread of cancer from the primary tumor to distant sites, accounts for the majority of cancer-related deaths. This complex process involves tumor cell detachment, invasion into surrounding tissues, entry into blood vessels, survival in circulation, and colonization of secondary sites. Key factors in metastasis include changes in cell proliferation, loss of anchorage dependence, and activation of oncogenic pathways. While much has been learned from mammalian models, particularly mice, many aspects remain poorly understood. The Drosophila model offers unique advantages, with its powerful genetic tools, whole-organism imaging capabilities, and insights into host-tumor interactions, to advance our knowledge of the key processes that drive metastatic events. Multispecies approaches, including Drosophila, are essential for advancing our understanding of metastasis and may lead to breakthroughs not achievable through single-species studies.