The 1906 U.S. Open was the 12th U.S. Open, held June 28–29 at Onwentsia Club in Lake Forest, Illinois, a suburb north of Chicago. Alex Smith won the first of his two U.S. Open titles, seven strokes ahead of runner-up Willie Smith, his younger brother and the 1899 champion. For the first time, no player from the inaugural U.S. Open in 1895 played in the tournament. Horace Rawlins, the winner of the first tournament, had played in every U.S. Open since then but did not play this year.