Yann was born in Versailles, France in 1948, thew son of Sophie Gallois-Bonnal, the daughter of the French composer/organist Joseph-Ermend Bonnal. She was a pianist, teacher, and worked at the Lazare Lévi. Yann lived in New York as a young child with the painter Frank Mason and his wife Phyllis Mason-Harriman, also a painter, and took piano lessons there at the age of 7. After returning to France at age 10, he took theater lessons in Paris, including those of Patrick Antoine, and appeared in a few plays and in the cinema.He became interested in the life of Christ. After studying at the North Ireland Bible School (Belfast) he was the founding editor of the journal Horizons Chrétiens from 1975 to 1990.

Yann Opsitch is the author of several works in French, "Paroles du Christ sur la Montagne", "En Esprit et en Vérité", "La Sagesse et l'Adversité", "Le Cœur et l'Invisible", "Le Dieu de la Création et de la Révélation". His  book in English Let us Come Before his Presence: 365 days to learn, meditate and pray from the Psalms and the Sermon on the Mount, was published in 2021, and Dialogues on Revelation with John the Apostle appeared the next year. He holds several degrees inBible, Biblical languages; Theology, Literature, and Conflict management. Professor Opsitch currently lives in Abilene, Texas). He writes, speaks, and coordinates online Bible and Theological School for the French-speaking world. His website is www.yannopsitchauthor.com.

Yann is married to Rita and is the father of three children and a grandfather of six grandchildren.