Thomas Fahr Steyer is an American businessman, philanthropist, environmental advocate, and Democratic political activist. He founded the San Francisco hedge fund Farallon Capital in 1986, serving as its co-senior managing partner until leaving the firm in 2012. He then became active in climate advocacy and Democratic politics, founding NextGen America and co-founding a climate change-focused investment firm called Galvanize Climate Solutions. Steyer is a billionaire, with an estimated net worth of $2.4 billion as of 2026.