Isin is a common Turkish given name. In Turkish, "Isin" means "beam (of light)", "ray (of light)", and "gleam".

Isin (Sumerian: I₃-si-in^ki, modern Arabic: Ishan al-Bahriyat) is an archaeological site in Al-Qadisiyyah Governorate, Iraq. Excavations have shown that it was an important city-state in the past.

An International Securities Identification Number (ISIN) uniquely identifies a security. Its structure is defined in ISO 6166. Securities for which ISINs are issued include bonds, commercial paper, stocks and warrants. The ISIN code is a 12-character alpha-numerical code that does not contain information characterizing financial instruments but serves for uniform identification of a security at trading and settlement.