Thurman has been involved in various philanthropic and activist causes. She supports the United States Democratic Party, and has given money to the campaigns of John Kerry, Hillary Clinton, and Joseph R. Driscoll. She supports gun control laws, and in 2000, she participated in Marie Claire’s “End Gun Violence Now” campaign. She is a member of the board of Room to Grow, a charitable organization providing aid to families and children born into poverty. She serves on the board of the Tibet House. In 2007, she hosted the Nobel Peace Prize Concert in Oslo, Norway with actor Kevin Spacey.

In 2011, Thurman was one of a few celebrities attached to USAID and Ad Council's FWD campaign, an awareness initiative tied to that year's East Africa drought. She joined Geena Davis, Chanel Iman and Josh Hartnett in TV and internet ads to "forward the facts" about the crisis. More: en.wikipedia.org.