With development, people around the world have become wealthier and live longer. At the same time, development can lead to growing inequalities within and between nations. This paper analyses inequalities related to disability and how they vary across countries by development level. Using internationally comparable data on disability inequalities in 40 countries, we assess disability inequalities through the use of regression analyses with a variety of development measures. Results support the hypothesis only partially: disability inequalities related to education, employment, and multidimensional poverty are found to be significantly larger in countries at higher levels of development. However, this is not the case for rates of access to water, sanitation, clean fuel, electricity, housing, and assets. These results, overall, hold when using different development and outcome indicators, and when focusing on specific subgroups of the population. The potential implications of these findings are discussed. Further research is needed to understand, for education and employment, the factors and processes that contribute to larger disability inequalities in countries at higher levels of development and what strategies might be pursued to reduce them.