At the age of 12, Hou became the youngest player ever to take part in the Women's World Championship and the Chess Olympiad (Turin 2006). In June 2007, she became China's youngest National Women's Champion ever. In 2010, she became the youngest World Chess Champion in chess history (men's or women's) by winning the Women's World Chess Championship 2010 in Hatay, Turkey, at the age of 16. She then defended her title by defeating Indian Koneru Humpy in the Women's World Chess Championship 2011.