Who is the greek god of law?

There were several Greek gods and goddesses associated with law:

Nomos was the god of law, and his wife Themis and daughter Dike were goddesses of justice. Nemesis is sometimes also cited as a goddess of law (in terms of retributory punishment). Eunomia is called the goddess of Law and Order. Dike, Eunomia and Eirene (goddess of peace) are often referred to collectively as Horae, goddesses of order and justice.