William Kiernan Haywood (born April 21, 1937) is an American former pitcher, coach, manager and farm system official in professional baseball.

He threw and batted right-handed, stood 6 feet 3 inches (1.91 m) tall and weighed 205 pounds (93 kg).

Signing his first pro contract at age 27, he played his entire professional career for the Washington Senators' organization and appeared in 14 Major League Baseball games for the 1968 Senators, for whom he worked in 23 innings, allowed 27 hits and 12 bases on balls, registered ten strikeouts, and had an earned run average of 4.70.

[1] As a minor leaguer, he compiled a win–loss record of 47–37 with an earned run average of 3.03 in 165 games.

He also served in professional baseball as a minor league coach and manager for the Senators/Texas Rangers franchise and as field coordinator and assistant player development director for the Seattle Mariners.