Hsiao was born on January 1, 1938 in Kaohsiung. His grandfather was a senior preacher in a Presbyterian church, his father was a highly regarded dentist who had studied in Japan and was also a senior church member, and his mother had studied piano in Japan early on.
一九三八年元旦，蕭泰然出生於高雄市，他的祖父是基督長老教會的傳道人，留學日本的父親是有名的齒科醫師兼教會長老，母親則是早期的留日鋼琴家。