Cardinal Patabendige Don was born on November 15, 1947 in Polgahawela, Sri Lanka.
He was ordained a Priest on June 29, 1975 for Colombo, Sri Lanka. On June 17, 1991 he was appointed Auxiliary Bishop of Colombo, Sri Lanka as well as Titular Bishop of Cabarsussi. He was ordained Bishop on August 31, 1991.
On November 2, 1995 he was appointed Bishop of Ratnapura, Sri Lanka, and remained there until October 1, 2001 when he retired upon his appointment as Official of the Congregation for the Evangelization of Peoples.
On April 29, 2004 he was appointed Titular Archbishop of Umbriatico, and Apostolic Nuncio to Indonesia and Timor-Leste. On December 10, 2005, he was appointed Secretary of the Congregation for Divine Worship and the Discipline of the Sacraments.
On June 16, 2009 he was appointed Archbishop of Colombo, Sri Lanka, and was installed there on August 5 of that year.
He was elevated to Cardinal on November 20, 2010 and appointed Cardinal-Priest of San Lorenzo in Lucina. He was installed on February 13, 2011.