Si Tianfeng (, Sī Tiānfēng, born June 17, 1984, in Xintai, Shandong) is a Chinese race walker. He represented China at the 2008 Beijing Olympics, finishing 17th. He also competed in the 50 km walk at the 2009 Chinese National Games and won the bronze medal. Si set a Games record to take the gold medal in the 50 km walk at the 2010 Asian Games. He was fourth at the World Race Walking Cup that year.