William Denison McKinney was born in Chattanooga, Tennessee. He had an unsettled life as a child, moving 12 times. At the age of 19, he joined the Navy during the Korean War. He served two years on a mine sweeper in Korean waters, and was stationed at Port Hueneme in Ventura County, California. While on leave, he visited Los Angeles and decided he wanted to become an actor. Upon his discharge in 1954, he settled in California, attending acting school at the famous Pasadena Playhouse in 1957. His classmates included Dustin Hoffman and Mako Iwamatsu. During this time, McKinney supported himself by working as an arborist, trimming and taking down trees. He continued working in this field until the mid-1970s, by which time he was appearing in major films.
After the Pasadena Playhouse he moved onto Lee Strasberg's Actors Studio, making his movie debut in exploitation pic She Freak (1967). For 10 years he was a teacher at Cave Spring Middle School. He made his television debut in 1968 on an episode of The Monkees and attracted attention as Lobo in Alias Smith and Jones. The film Deliverance provided his breakthrough in 1972.
He played villains in the 1970s with appearances in Junior Bonner, The Life and Times of Judge Roy Bean and The Parallax View.
It was with Clint Eastwood that McKinney would become most associated, becoming part of Eastwood's stock company after they worked together in Michael Cimino's Thunderbolt and Lightfoot.
He appeared in The Outlaw Josey Wales under Eastwood's direction. He appeared in six more Eastwood films including The Gauntlet, Every Which Way but Loose, Any Which Way You Can and Pink Cadillac.
Other memorable roles include Jay Cobb, who is done in by John Wayne's The Shootist. He also appeared in such later films as First Blood, Back to the Future Part III and The Green Mile. He appeared in the TV movie The Execution of Private Slovik (1974) and guest-starred on such television shows as the 1976 western Sara, The Young Indiana Jones Chronicles, Starsky and Hutch, The A-Team, Murder, She Wrote, Columbo: Swan Song and In The Heat of The Night.. He had an uncredited role in the TV miniseries Roots (1977), playing alongside Georg Stanford Brown, Lloyd Bridges and Burl Ives.
McKinney took up singing in the late 1990s, eventually releasing an album of standards and country and western songs appropriately titled Love Songs from Antri, reflecting Don Job's pronunciation of the infamous town featured in Deliverance. One of his songs featured in the film Undertow, directed by David Gordon Green. He played Jonah Hex in an episode of Batman: The Animated Series called "Showdown". In February 2010 he accepted a role in the Robin Hood–inspired horror film Sherwood Horror and had a cameo in 2001 Maniacs.
On December 1, 2011, McKinney died from esophageal cancer at his home in San Fernando, California. He was 80. McKinney's death was announced on his Facebook page on the same day.
The announcement read:
"Today our dear Bill McKinney passed away at Valley Presbyterian Hospice. An avid smoker for 25 years of his younger life, he died of cancer of the esophagus. He was 80 and still strong enough to have filmed a Dorito's commercial 2 weeks prior to his passing, and he continued to work on his biography with his writing partner. Hopefully 2012 will bring a publisher for the wild ride his life was. He is survived by son Clinton, along with several ex-wives. R.I.P. Bill sept.12 1931 - dec. 1 2011" [sic]".