Tri Harsono was born to a military family with his father a member of the air force.[2] Tri Harsono was educated at Stella Maris Middle Seminary in his home city of Bogor for four years. He then proceed to the Major Seminary of St. Peter and St. Paul in Bandung, and afterwards conducted a study of philosophy and theology at Parahyangan Catholic University, also in the city of Bandung.[2] On 5 February 1995, Tri Harsono was ordained a priest of the Roman Catholic Diocese of Bogor,[1] by then-bishop Cosmas Michael AngkurO.F.M.[3]
Tri Harsono's first assignment after being ordained was being the pastor at the Immaculate Maria Parish in Rangkasbitung, until 1996, after which he joined the advisory staff at his alma mater, Stella Maris Intermediate Seminary, in Bogor until 1998. He then undertook Arabic language and cultural studies at the Dar Comboni Institute for Arabic Studies in Cairo, Egypt in the first year and continued at the Pontifical Institute of Arab and Islamic Studies in Rome, Italy.[3]
