William Clarke Bordley (born January 9, 1958) is an American former Major League Baseball pitcher with the San Francisco Giants.

Bordley is a two time California Player of the Year and high school All American, who led the Knights to the 1975 Max Prep National Championship at Dodger Stadium.

In his freshman year with the USC Trojans baseball team, Bordley went undefeated with a 14–0 win–loss record and led the Pacific-10 Conference in strikeouts and wins.

In 1977 Bordley was named the Pacific 8 Athlete of the Year ahead of USC’s football Charles White and UCLA’s basketball David Greenwood.

Bordley started and won the final game of the 1978 College World Series, shutting out Arizona State University into the 8th inning.

In 2014, Bordley joined Rod Dedeaux, Fred Lynn, Rich Dauer, Steve Kemp and Roy Smalley as USC's six inductees to the College Baseball Hall of Fame.

In 1981, MLBPA President Marvin Miller, won an arbitration case supporting Bordley's contention that his Major League contract and bonus were salary, resulting in additional accrued pension benefits.

After only one year in the minors, the Giants promoted Bordley to the Major Leagues and put him in their starting rotation, joining Vida Blue, as left handed starters.

Bordley was compelled, via subpoena, to testify through the Office of Independent Counsel headed by Ken Starr, in the matter concerning the president and White House intern, Monica Lewinsky.

Bordley provided oversight on top secret investigations, including the counterfeiting of United States currency, fraudulent international banking operations and protection assignments in over 50 countries.