Mario Grech (born 20 February 1957) is a Maltese Catholic prelate who has served as Secretary General of the Synod of Bishops since 2020.

He then fulfilled pastoral assignments at the Cathedral of Gozo, in the National Shrine of Ta' Pinu, and the parish of Kerċem.

[1] He received his episcopal consecration on 22 January 2006 from his predecessor in Gozo, Bishop Nikol Joseph Cauchi.

[5] In 2011, he joined other Maltese bishops in advising Catholics to defeat a referendum that would allow the legislature to consider legalizing divorce.

[7] Speaking to the Synod in October 2014, Grech said that "the doctrine of the faith is capable of progressively acquiring a greater depth" and that addressing people in complex familial relations, or homosexuals or parents of homosexuals, "It is necessary to learn to speak that language which is known to contemporary human beings and who acknowledge it as a way of conveying the truth and the charity of the Gospel.

"[8] With Archbishop Charles Scicluna of Malta, Grech co-authored the Maltese bishops' pastoral guidelines on Amoris Laetitia, released in January 2017, which stated that in certain cases a divorced Catholic who remarried might receive Communion after "honest discernment".

[16] On 4 July 2020, Pope Francis named Grech a member of the Pontifical Council for Promoting Christian Unity[17] In October 2020, during the COVID-19 pandemic, Grech said:[18] It is of concern that someone feels lost outside of the Eucharistic or worship context, for it shows an ignorance of other ways of engaging with the mystery.

[23] In a 2024 interview, Cardinal Grech stated his belief in how synodality can help the Church move from “uniformity of thought” to “unity in difference,”.