<p dir="ltr"><b>Background:</b> Though ethics has been recognized as an important aspect of engineering education, there is not a definitive consensus on what ethical engineering is. This dissertation seeks to understand what constitutes ethical behaviors in engineering by distinguishing them from other normative behaviors.</p><p dir="ltr"><b>Purpose:</b> This study aims to understand what ethical engineering looks like in practice by addressing the research question: To what extent do engineering ethics experts agree when normative behaviors in engineering are also ethical in nature? While definitions of what constitutes ethical engineering practice are varied in the literature and have been debated theoretically by scholars, this study adopts an empirical approach to understand how experts in engineering ethics conceptualize ethical behaviors in engineering.</p><p dir="ltr"><b>Methods:</b> This dissertation study uses a Delphi process to build consensus among experts on what behaviors constitute ethical engineering practice. The Delphi panel consisted of 27 scholars, educators, and practicing engineers with expertise in engineering ethics who provided iterative feedback across three rounds of data collection through questionnaires. Round 1 generated 25 statements of normative behaviors in engineering. Round 2 prompted panelists to judge the ethicality of each behavior. Round 3 presented panelists with the aggregated responses and opinions from the previous round and invited them to revise their judgments.</p><p dir="ltr"><b>Findings:</b><b> </b>The results of the Delphi process identified areas of consensus and disagreement among the panel on which normative behaviors in engineering are generally considered ethical or non-ethical in nature. Of the 25 statements, panelists agreed that 20 of the behaviors tended to be ethical in nature and one behavior tended to be non-ethical in nature, while the remaining four statements did not yield consensus.</p><p dir="ltr"><b>Contribution:</b> This research aims to provide clarity around what constitutes ethical behaviors in engineering by differentiating them conceptually from other normative behaviors in engineering practice. The empirical approach taken in this study has implications for research, teaching, and assessment in engineering ethics education. Specifically, the questionnaire developed through the Delphi process can be deployed to study engineering students and practitioners to make broader claims about what is ethical in engineering.</p>