太陽花學運
Shortly after Tsai Ing-wen founded Thinking Taiwan in August 2012, Hsiao Yeh was one of the first invited to join. In March 2013, Hsiao Yeh participated in an anti-nuclear demonstration planned by Green Citizens’ Action Alliance and held around the Presidential Office. Days later, he and another former CMPC colleague, , among others, started the Five Six Movement, in opposition to nuclear technologies. A wide-ranging group that included Hsiao Yeh, Lee Yuan-tseh, Wei Te-sheng, Giddens Ko, and Kevin Tsai founded the Anti-Nuclear Fathers Front with the same goal, on Father's Day. In November Hsiao Yeh was invited to the Zero-Nuke Festival hosted by the Green Citizens’ Action Alliance. He was largely supportive of the Sunflower Student Movement in 2014. Hsiao Yeh joined the 2018 Taipei mayoral campaign of political independent Ko Wen-je as campaign director.