On July 3, 1984 (St. Thomas the Apostle's Feast Day is July 3 ), the Parish was founded. Its boundaries are: North - Santa Catalina Mountains South - Rillito River/Tanque Verde Wash East - West side of Sabino Canyon Road West - East side of Campbell Avenue July 7, 1984 First Mass was said in the auditorium of Sunrise Elementary School; affectionately referred to as "St. Sunrise." All Masses and Parish activities happened there until mid-1985. October, 1984 Parish Building and Parish Finance Committees were formed. January, 1985 Douglas Seaver & Associates was hired as Master Plan architect. June 22, 1985 Worship services move to the 'modular building' on premise. April 6, 1986 Groundbreaking May 12, 1986 Phase I construction begins April 19, 1987 (Easter Sunday) First Mass celebrated in the Church Phase I of the Parish Master Construction Plan completed (Church and Parish Office) January 17, 1988 Bishop Manuel Moreno presided at St. Thomas the Apostle's Liturgy of Dedication.
November 20, 1989 Phase II Construction begins - Parish Hall and classrooms May 6, 1990 Phase II Master Construction Plan completed January, 20 1993 Phase III Construction begins - Religious Education offices and classrooms July 18, 1993 Phase III Master Construction Plan - Religious Education building opens August 31, 1994 Preschool opens in Religious Education building April 8, 1997 Phase IV Construction begins - Chapel/Preschool March 22, 1998 Phase IV Master Construction Plan completed - Preschool April 19, 1998 Phase IV Master Construction Plan completed - Blessed Sacrament Chapel January, 2001 Mortgage burning June, 2011 Phase V Construction begins - O'Leary Hall, Rectory and Parish Hall kitchen remodel September, 2011 Phase V Construction Plan completed - Parish Hall kitchen remodel May, 2012 Phase V Master Construction Plan completed - Rectory June, 2012 Phase V Master Construction Plan completed - O'Leary Hall