Herman Constantin Vetterling (2 August 1849 – 5 September 1931), also known as Herman Carl Vetterling and by the pseudonym Philangi Dasa, was a Swedish-American Swedenborgian philosopher who converted to Buddhism in 1884 and took the Arabic-cum-Sanskritic name Philangi Dasa (meaning "Western Devotee").
Vetterling was born in Pjätteryd, Kronoberg, Småland, Sweden, and immigrated to the United States in 1873. He was naturalized in Philadelphia in 1880. He was one of the first Americans to officially embrace Buddhism. He founded The Buddhist Ray in Santa Cruz, California in 1887, which was the first Buddhist journal in the United States.
His most well-known work was Swedenborg the Buddhist, or The Higher Swedenborgianism: Its Secrets and Thibetan Origin, published in 1887. It is a fictional spiritual dialogue between Swedenborg, a Buddhist monk, a Brahmin, a Parsi, an Aztec Indian, an Icelander, an anonymous woman, and Vetterling himself. Six years later this work was translated into Japanese.
- California, Death Index, 1905-1939
- Dodin, Thierry. Imagining Tibet : Perceptions, Projections, and Fantasies. Wisdom Publications. pp. 171–172. ISBN 0-86171-191-2.
- U.S. Passport Applications, 1795-1925 for Herman Constantin Vetterling, 1922, County of Santa Clara
- Loy, David (1995). "The Dharma of Emanuel Swedenborg: A Buddhist Perspective". The Swedenborg Association. Retrieved 2007-03-31.
- "53. From Yoshinaga Shin'ichi (Nov. 24, 1999)". Retrieved 2007-03-31.