Fred Siegfried Hirsch (October 4, 1888 - September 11, 1979) was an American naturopath, entrepreneur, salesman, and author best known for his association with alternative health educator Arnold Ehret.

He co-founded Highland Springs Resort in 1927, where he associated with notable figures, including Albert Einstein, Ernest Hemingway, Roy Rogers, Bob Hope, and Elizabeth Taylor.

[1][3][4] For 65 years, Fred Hirsch and his wife Lucille published alternative health books, most notably Ehret's Mucusless Diet Healing System and Rational Fasting.

[2] On October 14, 1931, Arthur M. Hyde, Secretary of Agriculture, claimed Hirsch's marketing of Professor Arnold Ehret's Innerclean Intestinal Laxative Formula to be “false and misleading”.

[4] The product was released back to Hirsch under the condition that he pay a $4,000 bond and remove the advertisement on the packages, under the supervision of the United States Department of Agriculture.