Ilocano was originally written with the Baybayin syllabary, which is also used to write Tagalog, but this was gradually replaced by the Latin alphabet the Spanish arrived in the Philippines in the 16th century. One of the first publications in Ilocano was the Doctrina Cristiana of 1621.

The language is also known as Ilocano, Iluko, Iloco, and Iloko, and the Ilocano people call themselves Samtoy, a contraction from the Ilokano phrase saö mi ditoy, meaning 'our language here'.