Ġwann Frendo was born in Cospicua on 6 December 1937. He attended De La Salle College before joining the Dominican Order in 1954 and continued his studies in philosophy and theology at St Thomas Aquinas College, Rabat.
In 1962 he graduated with a licentiate in sacred theology from Rome's Pontifical University of St Thomas Angelicum. Two years later he acquired a doctorate in theology and master's degree in sacred liturgy from the Institut Catholique, Paris. Upon completion of his studies, Frendo was appointed lecturer in liturgy at St Thomas Aquinas College, a position he held until 1980 when he became a lecturer of liturgy at the faculty of theology, Tal-Virtu, Rabat until 1988. In 1988 he was appointed professor of liturgy at the faculty of theology, at the University of Malta and in 1990 head of the university's department of pastoral theology. Between 1967 and 1976 he also lectured on pastoral liturgy at INSERM.
In the Dominican province he served as prior of the Dominican community at Sliema between 1980 and 1989, parish priest of Jesus of Nazareth parish church in Sliema between 1981 and 1989, prior of the Dominican community of Ġwardamanġa from 1989 to 1995, and missionary works in Albania after that.
Frendo’s theological studies in sacred liturgy resulted in several publications. Between 1977 and 1980 he published more than 200 homilies in the popular series Omeliji Sena A, B u C. With his brother Fr.George Frendo, OP, he co-authored three books: L-Ewkaristija: Is-Sagrament tas-Sagrifiċċju tal-Kalvarju (1978), Is-Sena Liturġika (1983), and Is-Sagramenti: Laqgħat ma’ Kristu (1993). He also published other books on liturgical subjects in Maltese.
He died on 2 January 2003 at the age of 65.