Jacques-Louis Soret (French pronunciation: [ʒak lwi sɔʁɛ]; 30 June 1827 – 13 May 1890) was a Swiss chemist and spectroscopist.

Soret held the chairs of chemistry (1873-1887) and medical physics (1887-1890) at the University of Geneva.

[1] Soret determined the chemical composition and density of ozone and the conditions for its production.

He climbed Mont Blanc, where he was the first scientist to make actinometric measurements of solar radiation.

[6][1][2] In 1878, he and Marc Delafontaine were the first to spectroscopically observe the element later named holmium, which they identified simply as an "earth X" derived from "erbia".