Customary international law has a notable yet limited impact on Indian domestic law. India follows a dualist approach, meaning international law does not automatically become part of domestic law unless incorporated through legislation. However, customary international law—defined by consistent state practice and a belief in legal obligation (opinio juris)—can influence Indian courts if it does not conflict with existing statutes or the Constitution.

Indian judiciary has, in several cases, recognized and applied customary international norms, especially in areas like human rights and environmental protection, provided they align with domestic principles. Thus, while not directly enforceable on its own, customary international law can supplement Indian law and guide judicial interpretation, reflecting India's commitment to international legal standards.

Customary international law impacts Indian domestic law through the principle that **customs accepted as binding by the international community** are generally recognized, even without formal legislation. Indian courts have held that **customary international law is part of domestic law** unless it contradicts existing statutes or constitutional provisions. This means India may follow international norms related to human rights, environmental protection, or humanitarian law, even if they are not codified in Indian statutes. However, in case of conflict, **domestic law prevails**, and courts require legislative backing for enforcement of specific international obligations.

The relation between customary international law and domestic law can be understand by the two theories i.e Monoism and Dualism
Monoism- According to this theory the international law and domestic law are not the different things, the are related to each other or can say two side of same coin.
Dualism-According to this theory both the law are different from each other in its origin, its applicability and by its sanctions.
India is a example of of dualism i.e international law is not directly applicable in the india.For the application in india it is mendatory to make a law by indian parliament.
In the Visaka case the Supreme Court held that in the absence of law related to protection of woman on workplace the international customer law an be applied there.
conclusion is that we only apply international law in india if there is no any law is present in the country.

The relation between customary international law and domestic law can be understand by the two theories i.e Monoism and Dualism
Monoism- According to this theory the international law and domestic law are not the different things, the are related to each other or can say two side of same coin.
Dualism-According to this theory both the law are different from each other in its origin, its applicability and by its sanctions.
India is a example of of dualism i.e international law is not directly applicable in the india.For the application in india it is mendatory to make a law by indian parliament.
In the Visaka case the Supreme Court held that in the absence of law related to protection of woman on workplace the international customer law an be applied there.
conclusion is that we only apply international law in india if there is no any law is present in the country.