20th-century astrologers

Cyril Fagan (born Dublin, Ireland, May 22, 1896, died Tucson, Arizona, United States, January 5, 1970) was an Irish astrologer,
Generally considered the father - alongside Donald A. Bradley, the mother, of the western sidereal astrology. He is the creator with American astrologer Bradley of the Fagan-Bradley Ayanamsha.His books include:

Astrological Origins, Zodiacs Old and New St. Paul, Minn.: Llewellyn Publications, 1971.
Fixed Zodiac Ephemeris for 1948. Washington, D.C.: National Astrological Library, 1948.
A Primer of the Sidereal Zodiac
Zodiacs Old and New. Los Angeles: Llewellyn Publications, 1950.

A. Frank Glahn (1865–1941), was a German mystic, Germanic revivalist, and most notably a pendulum dowser. He was used by the German military in the Third Reich, not necessarily willingly.
Glahn was mentioned greatly in the book Reveal the Power of the Pendulum by Karl Spiesberger.
In 1920 A. Frank-Glahn's "Das Deutsche Tarot Buch" was published by Uranus Verlag, accompanied by a deck of cards "Deutsches Original Tarot", an Egyptian style deck, but unique. Glahn's book and cards became a German tarot bible, which survived up in the 1980s, published by Hermann Bauer Verlag. (K.Frank Jensen)

Lois Rodden (22 May 1928 - 5 June 2003) was an American astrologer and astrological data collector, known primarily as the founder of Astrodatabank. She was a pioneer in raising awareness of the sourcing of data being foundational in the credibility of astrology.