William Grover "Wild Bill" Hagy (June 17, 1939 – August 20, 2007) was an American baseball fan and cab driver from Dundalk, Maryland, who led famous "O-R-I-O-L-E-S" chants during the late 1970s and early 1980s from section 34 in the upper deck at Memorial Stadium.

[1] Hagy grew up in Sparrows Point, Maryland, and drove an ambulance, an ice cream truck, and eventually a cab until he retired in 2004.

[1] Hagy's fame led him to meet presidents such as Jimmy Carter and Ronald Reagan, and to get writeups in The New York Times.

At the end of the last game prior to the ban’s enactment, Hagy downed ten bottles of beer before tossing his cooler onto the field in protest.

[8] Hagy returned to Camden Yards on September 6, 1995 – the night Cal Ripken Jr. broke the longtime record for consecutive games played.