Koenraad Elst is a Flemish author, known primarily for his adherence to the Hindutva ideology and support of the Out of India theory, which is universally regarded as pseudo-historical by mainstream scholarship. Scholars accuse him of harboring Islamophobia.

Indigenous Aryanism, also known as the Indigenous Aryans theory (IAT) and the Out of India theory (OIT), is the conviction that the Aryans are indigenous to the Indian subcontinent, and that the Indo-European languages radiated out from a homeland in India into their present locations. It is a "religio-nationalistic" view on Indian history, and propagated as an alternative to the established migration model, which considers the Pontic–Caspian steppe to be the area of origin of the Indo-European languages.