Sayaka Aoki (青木 沙弥佳, Aoki Sayaka, born 15 December 1986 in Gifu Prefecture) is a Japanese track and field sprinter and hurdler, who specializes in the 400 metres sprint and 400 metres hurdles. She competed for her country as part of the Japanese women's 4 × 400 metres relay team at the Summer Olympics in 2008 and the World Championships in Athletics three times (2007, 2009, 2015). She has been a four-time medallist in the relay at the Asian Athletics Championships (2007, 2011, 2013, 2017), including a gold medal in 2011. She won her first major international medal in the hurdles – a bronze – at the 2017 Asian Athletics Championships.