[12]: 8 [16] In the summer of 2000, Somerhalder starred in the short-lived WB series Young Americans, a spin-off of Dawson's Creek.

In 2002, Somerhalder played bisexual character Paul Denton in Roger Avary's adaptation of Bret Easton Ellis' novel, The Rules of Attraction, alongside James Van Der Beek, Shannyn Sossamon, and Jessica Biel.

[26][27][28] In 2020, Somerhalder shot footage for and served as an executive producer on the film Kiss the Ground, a documentary centered on regenerative agriculture.

[30] In a 2024 interview, Somerhalder revealed that he had retired from acting a while back after relocating outside of Los Angeles, though he would still be involved in producing and environmental activism.

[38] For his second campaign, Somerhalder teamed up with The Vampire Diaries co-star Paul Wesley to release a limited edition shirt designed by a fan, with the words "Blood Brothers Since 1864.

[40] On December 8, 2010, Somerhalder's 32nd birthday, he launched the "Ian Somerhalder Foundation" which he hopes will educate people on the importance of protecting the environment and animals: "Instead of gifts this year, my birthday wish is that we come together and raise funds to support projects that protect our habitat and nurture our furry friends.

[41][42] To spread awareness for his foundation, Somerhalder sponsors and often walks in Mardi Paws, a parade and organization held in his hometown of Covington.

[43] He opposes GMO foods and factory farming, and supports ecologist Allan Savory in his crusade to let cows graze in sync with nature to enrich soil, enhance biodiversity, and reverse climate change.

In 2011, Somerhalder visited Savory in Africa and announced he was making a documentary about him with the goal of winning him a Nobel Prize.

[44][45] Somerhalder is also a celebrity campaigner for RYOT, a Los Angeles-based media company known for RYOT.org, its cause-based, take action online news source.