The 2005 WGC-American Express Championship was a professional golf tournament held October 6–9 at Harding Park Golf Course in San Francisco, California. It was the sixth WGC-American Express Championship tournament, and the third of three World Golf Championships events held in 2005. World number 1 Tiger Woods won the tournament to capture his fourth WGC-American Express Championship and his tenth World Golf Championships title. Woods defeated John Daly on the second hole of a playoff when Daly missed a two-foot (0.6 m) putt for par.