O'Neill's focus is on how conceptualizing organizational culture as a function of emotions (e.g., compassion, pride, joy, anger) and gender enhances the link between culture and a number of individual, team and organizational processes and outcomes, including decision-making, attitudes, career success, health behavior, corporate strategy, and financial performance. She's examined the careers of masculine women, bullying in female-dominated workplaces, and work-family balance.

Prior to coming to Mason in 2010, O'Neill was a visiting assistant professor of management in The Wharton School at the University of Pennsylvania, and assistant professor of management in the Terry College of Business at the University of Georgia.

O'Neill received her PhD in organizational behavior from the Stanford Graduate School of Business, and a BS from the University of Maryland-College Park.