John C. Maher (born 22 January 1951) is an Irish-British linguist, academic and author, professor of linguistics at International Christian University, Tokyo, Japan.

He has pioneered frameworks for the description of multilingualism in Japan.

He also developed the concept of metroethnicity as a hybrid, portable, lifestyle ethnicity used for aesthetic effect.

He was a British Council Lecturer at De La Salle University, Manila.

He is a founding member of Nihon Gengo Shakai Kagakkai 日本言語社会科学会 (Japan Association of Sociolinguistics).