Most Rev. Samuel Mar Irenios born on 13 May 1952 hails from Kadamminitta in Pathanamthitta District of Kerala, India in the Major Archieparchy of Trivandrum. His parents are late K. C. Thomas and Annamma. After his High School Education in Kadammanitta, he joined the St. Aloysius Minor Seminary Trivandrum. On completing the bachelorís degrees in Philosophy and Theology from St. Josephís Pontifical Seminary Aluva he was ordained priest on 22 December 1978 by Most Rev. Benedict Mar Gregorios. He completed secular degrees of BA, MA, MPhil and PhD from the University of Kerala. After being Appointed Lecturer in Mar Ivanios College, he later served as the Principal of St. Johnís College Anchal and retired as the Principal of Mar Ivanios College Trivandrum. From 1979 he served several parishes such as Erathumpamon, Muttathukonam, Pampukala, Vattakarikkam, Kuttichal, Vengode, Manjakala, Kunnapuzha, Kalliyal, Thirumala, Chalai, Palayam, Thiruvallam, Karakulam, Kallayam, Chenckalchoola, Anchal, Thazhamel and Ozhukuparackal as parish priest. He served as the Syncellus of the Major Archieparchy of Trivandum. Languages known are Malayalam, English and Syriac.
He was appointed the Auxillary Bishop of the Major Archieparchy of Trivandrum on 25 January 2010. He was ordained Auxillary bishop on 13 March 2010.