The name Inez is a feminine given name derived from the Spanish and Portuguese forms of the name Agnes, which in turn comes from the Greek word "hagnos" meaning "pure" or "chaste." The earliest known use of the name Inez dates back to the Middle Ages in the Iberian Peninsula.

Inez was a popular name among the nobility and royalty of medieval Spain and Portugal. One notable historical figure was Inez de Castro, a Galician noblewoman who was the lover and posthumously recognized wife of King Pedro I of Portugal in the 14th century. Their tragic love story became a popular subject in literature and art.

In the 16th century, the name Inez gained wider usage across Europe, particularly in France and England, where it was sometimes spelled as Inez or Ines. During this period, the name was associated with the ideals of purity and virtue, which were highly valued in Catholic and Protestant cultures.

One of the earliest recorded examples of the name Inez is found in the works of the English playwright William Shakespeare. In his play "Much Ado About Nothing," written around 1598-1599, a character named Inez is mentioned briefly.

Throughout history, several notable women have borne the name Inez. These include Inez Milholland (1886-1916), an American suffragist and labor activist; Inez Jastak (1885-1980), an American psychologist and pioneer in the field of intelligence testing; and Inez Courtney (1916-1975), an American actress and singer who appeared in numerous films and television shows in the mid-20th century.

Other famous individuals with the name Inez include Inez Tenenbaum (born 1951), an American politician and former chairwoman of the U.S. Consumer Product Safety Commission, and Inez Haynes Irwin (1873-1970), an American author and feminist activist known for her novels and essays on women's rights.