This dissertation is an ethnography of how archaeologists address inequalities in science and technology, advance epistemic justice, and challenge (neo)colonial structures of knowledge production. The central question is: how do professionals who work with ancient human remains in North and South America mobilize ethical principles and practices in their collaborations with Indigenous and local communities? Scholarship in both Science and Technology Studies (STS) and archaeology has shown that community collaboration benefits both researchers and community members, fostering the production of decolonial and antiracist knowledge. While these works indicate that collaboration promotes ethical research, they do not fully explore the ethical tensions such collaborations create. Where Knowledges Meet interrogates some of these tensions, examining how the recent adoption of a series of ethical principles—collaboration, consultation, repatriation, and others— has become a standard for reliable and credible knowledge. By working with interlocutors in North and South America, my work reveals how power structures in science affect ethical values and understandings of ethical research. Where Knowledges Meet draws from thirteen months of ethnographic fieldwork and interviews with Indigenous, non-Indigenous, and settler archaeologists working at two of the earliest professionally excavated sites in the world, in Minas Gerais, Brazil and Ohio, U.S. It argues that, in their search for epistemic justice, archaeologists have mobilized ethics through novel approaches that challenge traditional understandings of science and scientific progress. While these new understandings are celebrated as progressive, ethical, and democratic, they fail to recognize global hierarchies of knowledge— shaped by geopolitics of knowledge— thereby normalizing U.S. perspectives on ethics, science, and race as universal. By revealing how (neo)colonial forms of knowledge and racialized appeals to scientific ethics shape contemporary research with human remains, Where Knowledges Meet illuminates the connections between coloniality, race, and ethics in scientific practice, advancing understandings of the co-production of science and ethics by bringing Science and Technology Studies (STS) literature into conversation with Indigenous and Latin American Studies.