Fr. Sia was born in Manila, Pilippines. After graduating from the University of Philippines, College of Medicine, he worked as a research associate before moving to the United States to pursue a doctorate. It was on Pentecost Day of 2003 while in the Iowa City, when he received the courage to accept the calling to the priesthood.
He studied Theology at the University of St. Mary of the Lake Mundelein Seminary and was ordained on May 10, 2008 in Davenport's Sacred Heart Cathedral by Bishop Martin Amos.
Fr. Sia is currently serving as a pastor at St. Joseph Catholic Church in Columbus Junction, Iowa.