Yoannis Lahzi Gaid was born in Cairo, Egypt, in 1975. He studied at the Coptic Catholic seminary in Cairo. He was ordained priest for Coptic Catholic Patriarchate of Alexandria, Egypt in 2001.
In 2002 He studied at the Pontifical Oriental Institute, earning a doctorate in the canon law of the Eastern Churches.
In 2006 He edited a volume of texts from the Code of Canon Law for the Eastern Churches.
In 2007 He attended the Pontifical Ecclesiastical Academy and joined the diplomatic service of the Holy See. His assignments included stints in the Democratic Republic of the Congo and Gabon, and as charge d’Affaires of the Apostolic Nunciatures to Jordan and Iraq. He also served as an Arabic translator for Pope Benedict XVI and Pope Francis at his general audiences and in meetings with Arabic-speaking diplomats and government officials.
In July 2011, Pope Benedict XVI appointed him a chaplain of His Holiness with the title monsignor.
In April 2014 Pope Francis appointed him as his Second Personal Secretary. He continues to work for the Secretariat of State as well. His appointment was interpreted as gesture of support for Eastern Catholic churches and dialog with the Arab and Muslim world.
In February 2019 Mgr Gaid participated in the Apostolic Journey of Pope Francis to the United Arab Emirates, where the Document on Human Fraternity for World Peace and Living Together, was signed in Abu Dhabi by Pope Francis and the Grand Imam of Al-Azhar, Ahmad Al-Tayyeb.
In February 2019 His Highness Shaikh Mohamed Bin Zayed Al Nahyan, Crown Prince of Abu Dhabi and Deputy Supreme Commander of the Armed Forces of the United Arab Emirates, has conferred the First Class Order of Zayed II on Monsignor Yoannis Lahzi Gaid, in recognition of his efforts to guarantee dialogue and coexistence between different religions.
In September 2019 Mgr Gaid was named as one of the first members of a Higher Committee of Human Fraternity. He was also named a member of its executive board.
In July 2020 Mgr Gaid left his service as Personal Secretary of Pope Francis and is currently the President of the Bambino Gesù Association and the Human Fraternity Foundation.