D. Singh is a common name that may refer to various individuals across different fields, including sports, academia, and business. Without specific context, it is challenging to pinpoint a particular person. The name "Singh" is often associated with individuals of Indian descent, as it is a common surname among Sikhs and Hindus. In sports, for example, D. Singh could refer to athletes who have made significant contributions in their respective disciplines. In academia, there may be researchers or professors with this name who have published works in various subjects. Overall, D. Singh represents a diverse range of individuals across multiple sectors.