This article examines cross-country variations in adult skills inequality and asks why skills in Anglophone countries are so unequal. Drawing on the Organization for Economic Cooperation and Development's recent Survey of Adult Skills and other surveys, it investigates the differences across countries and country groups in inequality in both skills opportunities and outcomes and uses pseudo-cohort analysis to establish trends over time and during the life course. The analysis shows that adults' skills in Anglophone countries, and particularly in the United States and England, tend to be more unequal than in other countries on a wide range of measures. This cannot be explained by intercohort differences, skills distributions among adult migrants, or levels and distributions of adult learning, but inequality in education levels provides a strong predictor of skills inequality among adults. Whereas research suggests that early selection drives skills inequality in compulsory schooling, certain forms of tracking, such as bifurcation into academic or apprenticeship/vocational education in upper secondary education, can have a mitigating effect.