As coach William Ernest Hayes (born October 24, 1957), nicknamed "Wild Bill",[1] is an American former catcher for the Chicago Cubs (1980–81).

Born in Cheverly, Maryland, Hayes grew up in North Platte, Nebraska and graduated from St. Patrick High School.

In 1978, his junior season at Indiana State, Hayes was an all-conference player and led the team with 13 home runs.

Hayes served as the bullpen catcher for the San Francisco Giants from 2003 to 2014, winning three World Series Championships (2010, 2012, 2014).

[6] He was removed as first base coach by the Giants after the 2016 season,[7] but remained on the staff in a non-coaching role.