Seicho-no-Ie, sometimes rendered Seicho-no Iye (生長の家 seichō-no ie [seːtʃoː no i.e]), is a syncretic, monotheistic, New Thought religion/philosophy, one of the Shinshūkyō (or new religious movements) in Japan that have spread since the end of World War II. It emphasizes gratitude for nature, the family, ancestors and, above all, religious faith in one universal God, inheriting its basic characteristics from Buddhism, Christianity and Shintoism. Seicho-no-Ie is the world's largest New Thought group. The phrase means "House of Growth".

In 1930, Dr. Masaharu Taniguchi, working as an English translator, published the first issue of what he called his "non-denominational truth movement magazine", which he named "Seicho-no Ie" to help teach others of his beliefs. This was followed by forty volumes of his "Truth of Life" philosophy by 1932. Over the next forty years he published an additional four hundred–odd books and toured many countries in Europe, South America, and North America with his wife Teruko, to lecture on his beliefs personally. Ernest Holmes, founder of Religious Science, and his brother Fenwicke were of great assistance to Taniguchi. Fenwicke traveled to Japan and co-authored several books, with one called The Science of Faith becoming a cornerstone of the denomination.